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The summer growing season may be winding down, but temperature extremes, smoke-filled skies, and who knows what all have caused many garden plants to behave strangely this year. For one thing, many plants took a lot longer than normal to get started. Our early heat wave, followed by a cold snap, and then scorching summer temperatures caused many plants to be confused about the seasons. Instead of following their normal progression of leaf and stem growth, followed by flowering and then fruiting, plants struggled early on to figure which task they should be performing. Small pepper plants are taking longer to get bushy, eggplants were late to bloom, and squash plants look as though they are starting the season all over again!  Zucchini plant putting out new growth in mid-October (Kate Russell)
My solution: cut off older leaves and lift plants skyward with tomato cages. It might not make a difference. Then again, it might. In my mind, getting leaves and fruit away from the soil eliminates one point of pest entry. It also improves airflow around the plants, reducing the chance of fungal disease. It looks pretty cool, too. And I’m still getting zucchinis.
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Fruit and nut trees make excellent additions to a landscape, but how do you know which trees to plant? The questions below will help you select the best fruit and nut trees for your landscape.  Immature almonds (Kate Russell) How big of a tree do you want? Fruit and nut trees are available in standard, semi-dwarf, and dwarf sizes. Standard fruit and nut trees can reach 20 feet in height and width, or more. Semi-dwarf trees grow 12-15 feet tall and wide, while dwarf trees only reach 8-10 feet. Smaller trees have the added advantage of being easier to care for and producing fruit sooner than larger trees. Some varieties tend to stay smaller naturally. Standard sized peach and nectarine trees, for example, rarely grow larger than 12-15 feet. Most dwarf trees can be grown in large containers. How big of a crop can you use? Different tree species produce different sized crops. Under ideal conditions, a mature dwarf apricot tree only produces 40 pounds of fruit, while a standard apricot tree might yield 240 pounds. Using the same amount of real estate, a dwarf apple tree might produce 200 pounds of fruit, a semi-dwarf apple can yield 400 pounds, and a standard apple tree might produce 600 pounds of apples! That’s a lot of applesauce!  Young apples take time to mature (Kate Russell) What is your Hardiness Zone? Hardiness Zones are geographic regions with specific annual minimum temperatures. This information helps you select plants appropriate to your microclimate. If you live in San Jose, California, you will want fruit and nut trees suited to Hardiness Zone 9 (a or b). How much sun does your yard get? Most fruit and nut trees need at least 8 hours of sunlight each day to be healthy and productive. Will you need a pollinator tree? Some fruit and nut trees are self-fertile. This means they have both male and female flowers and only one tree is needed. Other varieties need a second tree for cross-pollination. Self-fertile trees are significantly more productive when there is a second tree nearby. Which pests and diseases are in your neighborhood? Knowing ahead of time which pests and diseases are likely to affect your fruit and nut trees can help you select varieties that are resistant. This means less work for you.  Fresh nectarines in summer are a treat! (Kate Russell) How many chill hours does your yard get? Chill hours are the combined number of hours below 45°F experienced by a tree each year. Without adequate chill hours, trees will generally not produce. Most of northern California gets 800 to 1,500 chill hours, but Santa Clara County averages less than 450 chill hours each year.
Fall is the best time to plant bare root trees in San Jose, California, just be sure to plant them at the proper depth. This means the flare of the trunk and any grafting are visible above the soil level. For the first few years, when your fruit tree produces flowers, it will live a longer, more productive life if you remove those blossoms before they start turning into a crop. This gives the tree the time it needs to generate a healthy root system. Now start planting! A gooey, clear ooze dripping from your apricot, peach, or nectarine tree may indicate a fungal disease known as gummosis. Or, it might not.  Gummosis on almond tree (jacinta lluch valero) CC BY-SA 2.0 Gumming is a natural protective response used by trees to counteract environmental conditions, such as sunscald, frost damage, improper pruning, planting too deeply, excessive irrigation, and too much fruit production. Mechanical injuries caused by lawnmower collisions, rubbing branches, and outgrown tree supports can also cause gumming, as well as insect infestation by peach tree borers, flathead borers, and other boring insects, and by diseases such as Eutypa dieback, cytospora canker, Fusarium dieback, and bacterial spot.
When mechanical injury or environmental conditions are the cause, it’s usually pretty easy to see. When gumming is caused by insect invasions, you will normally see insects and bits of sawdust caught in the gum. When gumming is in response to disease, you need to read up on the possible diseases to know for sure what your tree has. Apricot gummosis symptoms Apricot gummosis starts out looking like blisters on branches and the trunk. As the disease progresses, the tissue around these lesions will begin to die and the tree will produce gum. As fungal spores grow and reproduce, cankers will form. Apricot gummosis pathogen Apricot gummosis is caused by Botryosphaeria dothidea fungi. Fungal spores enter through wounds. These fungi are opportunists, causing blueberry stem blight and cankers on a wide variety of plants. Trees suffering from lower limb dieback are commonly infected by this pathogen in their weakened state. Apricot gummosis prevention and treatment Apricot gummosis occurs most often in years with a cool, wet spring, followed by high temperatures. There’s nothing you can do about the weather, but there are steps you can take to prevent and treat apricot gummosis. Since gummosis generally occurs in trees that have been damaged in some way, protecting them from injury in the first place goes a long way toward preventing gummosis. Lawnmowers, weedwackers, careless pruning, borers, limb breakage, and other actions that can poke holes in a tree’s bark should be avoided. Whitewashing trunks and exposed branches can help prevent sunburn damage. Proper feeding and irrigation will keep your trees healthier in general. And always wait until your trees are dry before pruning. If apricot gummosis is present, all infected wood should be removed, spraying cutting tools with bathroom cleaner between each cut. This helps prevent infecting healthy wood. Cuttings should be removed from the property right away. Severe infections will require the use of fungicides. Research has shown that fungicides containing benomyl, fenarimol, iprodione, prochloraz, or tebuconazole. According to the study, “The best control was obtained with treatments of prochloraz mc alternated with mancozeb. Applications of bitertanol and fenarimol also significantly reduced the occurrence of cankers.” As with any time you are using fungicides or other potentially dangerous chemicals, read the label and follow directions exactly. Asian gypsy moths have just been spotted in Sunnyvale, California and officials are worried. You should be, too, if you live anywhere these pests have been found. A single Asian gypsy moth caterpillar can eat one square foot of foliage in a single day. Every day. For weeks.  Asian gypsy moth caterpillar (John H. Ghent and Manfred Mielke, USDA, bugwood.org) Public Domain And they love fruit and nut trees, along with oak, elm, sweetgum and more that 500 other plant species. If the leaf loss doesn’t kill your tree or shrub, it certainly becomes more susceptible to other pests and disease. Adding insult to injury, these caterpillars have hairs that can irritate your skin and may cause allergic reactions that can last two weeks. Spreading invasive pests A single female Asian gypsy moth can lay 500 to 1,500 eggs and mature moths can fly 20 to 25 miles from where they started. This means they can spread rapidly. They also hitch rides on shipping containers, RVs, firewood, patio furniture, and your shoes. These pests were first seen in the U.S. earlier this year (May 2020), in Snohomish County, Washington. One month later, these moths were found in Oregon, Georgia, Oklahoma, and South Carolina. Now they are in California. Did I mention that these pests travel quickly? Asian gypsy moths have the potential to wipe out entire forest ecosystems, not to mention your garden and landscaping. Once pests like these become established in an area, widespread quarantines of produce, flowers, plants, and lumber are often necessary. Different types of gypsy moths Also known as Hokkaido gypsy moths, these pests are not the same thing as European gypsy moths. European gypsy moths are bad news, too. In 2017, European gypsy moths defoliated one-third of the state of Massachusetts, resulting in the loss of one-fourth of its oak trees the following year. Invasive pests have the potential to cause devastating damage because many of them have no natural pests and indigenous trees and other plants have not evolved their own protections. There are several subspecies of Asian gypsy moth which all look very similar: Lymantria dispar asiatica, L. d. japonica, L. albescens, L. umbrosa, and L. post-alba. You don’t need to learn how to tell them apart (unless you’re into that sort of thing). What is important is learning how to recognize them and reporting them right away.  Male and female adult Asian gypsy moths (USDA Fact Sheet) Public Domain Asian gypsy moth description Easily mistaken for tent caterpillars or webworms, Asian gypsy moth caterpillars start out less than 1/8” long and tan. As they feed and grow, they may reach 3-1/2” in length, with two rows of blue and red spots along their backs. Fully mature caterpillars may have a mottled grey color that can range from yellow to black. Adult female moths are white and somewhat larger than most of our native moths, with a 3-1/2” wingspan. Males are grayish brown and smaller, with a wingspan of only 1-1/2”.  Cluster of Asian gypsy moth eggs and adults on tree trunk (John H. Ghent and Manfred Mielke, USDA Forest Service, bugwood.org) Public Domain Fuzzy buff or yellowish egg masses may be seen on tree trunks and branches, as well as fences, walls, and patio furniture. Each egg mass averages 1-1/2” wide by 3/4”, though they may be as small as a dime.
Asian gypsy moth control The first step in controlling these pests is prevention. Always inspect imported products carefully for signs of pests and place new plants in quarantine. Once they appear, it takes a concerted effort to control them. Washington state pest agencies are spraying Bacillus thuringiensis var. kurstaki or Btk. Btk is a soil bacteria that kills the Asian gypsy moth but is not harmful to pets, people, fish, or bees. Before you can spray Asian gypsy moths, you have to know where they are. The California Department of Food and Agriculture and the United States Department of Agriculture are currently placing 2,300 traps over 81 square miles of the Sunnyvale area. If you see one of these traps, please leave them alone. If an agency asks permission to place a trap on your property, please say yes. If Asian gypsy moths arrive in your garden, it is critical that you report sightings to State or Federal officials right away. If you live in California, you can use the Pest Hotline at 1-800-491-1899. Otherwise, contact your local County Extension Office. By reporting sightings to officials right away, they are coordinate their efforts more effectively. Why on Earth would you want to wash off a plant’s roots? Don’t roots prefer being covered with soil?
Very often, mass-produced trees, shrubs, and other woody plants are root bound by the time they reach market. Roots can often be seen circling around the inside of the container, looking for a way out. Left uncorrected, these roots can girdle and kill the plants. Washing the roots allows you to identify the primary roots and to correct any problems.
Soil interface
Soil interface refers the what happens to roots when they come into contact with a different type of soil. Very often, the soil used in mass-produced plants is a soilless mixture that contains a lot of pumice and organic material. You might expect that plants would simply move into the new soil in search of food and water, but they often don’t. When this happens, the plant usually dies. The same thing can happen when you transplant summer annuals from high quality potting soil into more compacted, residential soil. [Believe me, I speak from experience!] Washing off the roots and installing the plant in new or resident soil eliminates this problem. You can do the same thing when planting vegetable and flower seedlings, just be very, very gentle. Planting depth Root washing helps you to replant the newest member of your garden or landscape at the proper depth. Bagged and packaged plants are often surrounded with extra soil. This soil is often assumed, incorrectly, to mark the proper planting depth. Planting trees at the incorrect depth is one of the most common causes of tree death. You want to be able to see the outward flare of the trunk above the soil line. Slightly too high is far better than too low. Very often, planting holes are dug too deeply and not widely enough. Trees and their roots are best pictured like a goblet on a plate. The goblet represents the aboveground portion of the tree, while the plate represents the root system, spreading out laterally. The crown and any grafting union should always be above soil level and soil amendments are not recommended. If you suspect deficiencies in your soil, get it tested before adding anything, because too much of a good thing can be a bad thing. How to wash roots Now that you understand why root washing is a good idea, how do you do it?
That’s it. Now you can inspect, prune, and replant. Finally, rather than watering your trees and shrubs (and other plants) on a calendar schedule, invest in an inexpensive moisture meter. Containerized plants should be allowed to dry out to the point that soil pulls away from the edges of the container slightly, then water thoroughly. The water-stress symptoms of overwatering look very much like the symptoms of not enough water. Don’t guess. Help your plants thrive with root washing and proper planting depth. Raccoons are garden bandits and they can be a real problem. The iconic bandit masked face of a raccoon should be fair warning to gardeners and homeowners. Raccoons are smart, strong, and tenacious. They will devour zucchinis and tomatoes, harvest prized koi, steal eggs, and kill chickens.  Mother raccoons tour the neighborhood with their young, teaching them where to find food. (Kate Russell) Raccoon, the animal Raccoons (Procyon lotor) can reach 3 feet in length and weigh up to 55 pounds. They are mostly nocturnal and they hole up in brush piles, ground burrows, hollow trees, under decks, and in attics and garages. Raccoon litters, of 3 to 6 kits, are usually born in late spring and early summer. Raccoons are very quiet, and they are often intelligent enough to not be seen, so detecting them can be difficult. Until they start to eat. Raccoon, the thief Raccoons eat just about anything. They will scrounge your garbage cans and compost piles, wreak havoc on outdoor worm bins, and eat pretty much everything you grow in your garden. Corn is their favorite garden vegetable, but berries, tree fruit, nuts, and your other crops are all fair game to a raccoon. Like squirrels, raccoons are problem solvers. Research has shown that raccoons can recall the solution to a task for at least three years. Raccoon, the destroyer As mother raccoons feel the urge to create a den, they often look to buildings and uncapped chimneys as nesting sites. As she decorates the nursery, mother raccoon will often damage fascia boards, rip off shingles, shred attic insulation, dislodge heating and air-conditioning ducts, and dismantle rooftop ventilators. She will also designate one area as a personal port-o-potty, creating a nasty stench and staining the building materials. Even if the den is under a deck, the damage and smell can get bad. Many parasites catch a ride on raccoons. This act of phoresy can bring fleas, ticks, and other pests closer to your home. Raccoons can also carry roundworm, distemper, tetanus, rabies, and nearly a dozen other pathogens. Roundworm can be spread by inhaling infected feces and cases are on the rise. Raccoons infected with rabies may not show any symptoms at all, but they are responsible for over 1/3 of all human rabies cases in the U.S.
In order of importance and/or effectiveness, raccoon controls include:
In California, raccoons are classified as furbearers that can be harvested at certain times of the year. Nuisance raccoons can be taken by legal means at any time. It is illegal to relocate trapped raccoons without written permission from the Department of Fish and Wildlife. Uneducated relocating of wildlife causes far more problems than many people understand. Check with your local Department of Fish and Wildlife for the rules in your area. Research has not shown that chemical raccoon repellents work, so save your money. The same is true for home remedies. The bottom line in raccoon control is to reduce the food and shelter appeal of your yard. Raccoons are strong and can be vicious if cornered. If trapping is necessary, it is better to hire a professional. Most of us think of spring when it comes to actually putting seeds into the soil. Summers are dedicated to weeding and watering. Planter pots have all been washed and stored away for next spring, along with any leftover potting soil and maybe a bag of vermiculite. But planting season isn’t necessarily over, just because it’s summer.  Cabbage (Kate Russell) How much time is left to grow? The first thing you have to ask yourself before planting in summer is how long of a growing season you have left. If snow falls where you are by mid-October, you will have to pick some pretty fast growing plants before tucking your garden away for the winter. Here, in San Jose, California, we can plant crops year-round, but the list of plants is very different from one season to the next. Check your Hardiness Zone for first and last frost dates and then check seed packets for days-to-maturity or days-to-harvest information. There’s no sense watering and weeding a plant, only to have it killed by frost or snow before it can produce a harvest. Cool season crops In mild regions, summer is the best time to start thinking about cool season crops. Many winter crops take significantly longer than tomatoes and peppers to mature. Giving them a head start in summer means bigger harvests later in the year. Look at your garden and try to imagine what it will look like in one month, in two months, in mid-winter. As spring crops peak and then fade, you can introduce winter crops under the protective care of your summer garden. In some cases, summer plantings can even give your spring garden a boost.  Fennel (Kate Russell) Beneficial beans Most gardeners know that beans and other legumes are able to fix atmospheric nitrogen in nodules on their roots, with the help of certain soil bacteria. Once these plants start flowering, that nitrogen is no longer available. Up to that point, any neighboring plants will benefit from the extra nitrogen, giving them extra nutrients as they near the end of their productive lives. If you live in Zone 9b, or tend to have mild winters, July is your last chance to plant beans for the year. Find space for one more planting. These beans will be ready to harvest long after any spring planted beans will have worn themselves out. They will also provide nitrogen to whatever is growing nearby. Late summer is a good time to plant fava beans, another legume. These hardy legumes grow quickly, adding nitrogen to the soil and helping break up our heavy, compacted soil with their sturdy roots. The pods are pretty delicious, too.  Fava beans grow tall and fast! (Kate Russell) Zone 9b summer plantings While mid-summer is too late to start any more tomatoes, peppers, or squashes, there are many plants that can be planted twice in the same year in areas with gentle winters. Carrots, cauliflower, chard, cilantro, fennel, kale, kohlrabi, parsnips, peas, radishes, spinach, and turnips are all popular spring plantings that can be sown again in late summer. Collards, dill, endive, and lettuces will produce an excellent crop if planted in September and October. And Brussels sprouts should be started in summer so that they can be transplanted into the garden by August, September at the latest. The same is true for cabbages, Napa cabbage, leeks, and okra. Chayote fruit can be planted any time during the summer.  Endive makes a lovely border (Kate Russell) By planting year-round, you are providing for the soil microorganisms that help your plants grow. You will also be providing your family with fresh, healthful food without ever leaving your yard.
I discovered a new insect in my garden: the cuckoo wasp.  Cuckoo Wasp on pine needle (Wasrts) CC BY-SA 4.0 I was busy planting seeds and placing them in a sunny location, on my pumpkin ladder, when a flash of metallic green caught my eye. I looked for it and couldn’t find it, at first. But I knew I had seen it and I knew that metallic green either meant an insect or some plastic trash had flown in. In either case, I had to find it. Finally, there it was! An insect I had never seen before. It was probably no more than 1/4” long with an oblong body, a largish, rectangular head, and jointed, fringed antennae. The wings were as long as the body and when the sunlight hit it, the bright green really was beautiful. But I didn’t yet know if this was a good bug or a pest, so I captured it. Once I had it in a container, I could see that the underside of this new insect was just as bright green as the top. But I still didn’t know what it was.  Underside of cuckoo wasp (Kate Russell) I looked in my field guide, but couldn’t find it. I could have asked my entomologist friend in Colorado, but I already owed him a batch of brownies for my last ID request, so I went to social media and asked the hive mind. In no time at all, I had several friends telling me that my new guest was a mostly beneficial insect, called a cuckoo wasp. I say mostly beneficial because cuckoo wasps kill the larvae of other insects. Some of those other insects are pests and some of them are beneficial pollinators. There are over 3,000 different cuckoo wasps in the world and 166 species in California. They are also known as emerald wasps, jewel wasps, ruby wasps, and gold wasps, depending on the color. These wasps don’t look anything like the yellow jackets or paper wasps most of us see each summer. They look more like harmless beetles. There is debate about whether or not these insects can sting. I didn’t see any sign of aggression in my visitor, by your experience may vary.  Ruby cuckoo wasps feed on specific wasps that feed on honey bees (Frank Vassen) CC BY 2.0 Cuckoo wasps get their name because they lay their eggs in the nests of other solitary bees and wasps. Laying eggs in a bee’s burrow is no mean trick. Female cuckoo wasps watch sawflies and other solitary bees and wasps as they drag paralyzed spiders and other insects into their burrows, stocking up a larder for their offspring. The female cuckoo waits until the host flies off before sneaking inside to lay her eggs. Research has shown that cuckoo wasps are able to mimic the smell of their hosts, rendering them invisible within the darkness of a burrow. Particularly brazen cuckoo wasps will catch a ride on the paralyzed prey, carefully staying out of sight. This is dangerous business. Luckily for the cuckoo, if she is spotted, her brightly colored, heavily pitted exoskeleton is able to protect her from bites and stings. She is also able to curl up into a ball the same way a sowbug or an armadillo might. If she curls up inside an angry host’s burrow, the host has no other choice but to throw it outside unharmed. If you happen to spot one curled up, it may simply be taking a nap.  Sleeping cuckoo wasp (Katia Schulz) CC BY 2.0 Some cuckoo wasps are murderers and some of them are thieves. Parasitic cuckoos eat the offspring of solitary bees, wasps, hornets, sawflies, silk moths, and stick insects. The kleptomaniac cuckoos steal the food left for the host’s offspring.
It ends up that cuckoo wasps have very specific needs, as far as habitat goes. Adults feed on nectar from flowers in the carrot family, the sunflower family, and the spurge family. Cuckoo wasps are secretive and they move very quickly, which explains why I’ve never seen one before. But I hope I see them again! Ever since learning how easy it is to grow edibles at home, I keep finding foods that make my landscape look more interesting and my meals more delicious. I decided to see if I could grow my own paprika. It ends up I can and so can you!  Drying Hungarian paprikas (thomasheise) needpix.com You may be surprised to learn, as I was, that the paprika we buy in stores is simply dried and ground up sweet peppers (Capsicum annuum). In some cases, the peppers are smoked over oak wood or roasted. Tomato peppers (Capsicum annuum var. annuum) are the most commonly used, but pretty much any pepper can be used. Types of paprika Paprika is classified as ‘sweet’ or ‘hot’. Sweet paprika is made from the flesh, or pericarp, and only half of the seeds of sweet peppers. Hot paprika includes some of the seeds, stems, white part (placenta), and calyces (flower sepals) of sweet peppers along with chili peppers and cayenne peppers, for extra flavor and heat. Most of the paprika you buy in the store is a Hungarian sweet recipe, but cooks and aficionados take paprika more seriously than that. According to The Complete Book on Spices & Condiments With Cultivation, Processing and Uses, there are several grades of Hungarian paprika:
Spanish paprika (pimentón) is classified as mild (pimentón dulce), mildly spicy (pimentón agridulce) and spicy (pimentón picante). My dear friend gifted me with some delicious Turkish paprika - thank you, Steve! How about we create a new set of categories: store-bought and homegrown? Paprika peppers While practically any peppers can be used to make paprika, Hungarian and Spanish varieties are the most commonly used. Hungarian peppers tend to be 2 to 5” long, oblong to pointy, and thin-walled. These peppers are mostly mild with only a few exceptions. Spanish peppers are larger, ranging 5 to 9” long, are thick-walled and more susceptible to disease. Personally, I love these bell-shaped peppers. [Does anyone know where I can get seeds?]  Red and green paprika peppers (Reisefreiheit_eu) Public Domain How to grow paprika peppers Paprika peppers are perennials in Central America but they are grown as annuals everywhere else. Paprika peppers are grown the same way as other peppers, which means they need time, heat, and lots of sun exposure. You can grow them in the ground, in raised beds, or in large containers. But don’t try starting peppers until temperatures are well above 50°F. Plants should be spaced 12” apart. Like other peppers, paprika peppers need steady moisture but cannot tolerate soggy soil. Mulching around your pepper plants will help retain that moisture and stabilize soil temperatures, which will give you a bigger crop. Paprika pepper pests and diseases Aphids, flea beetles, and hornworms may attack your pepper plants, but row covers can provide good protection. Diseases include leaf blight, leaf spot, wilt diseases, and viral diseases, such as mosaic, are common. Too much direct sunlight can cause sunscald on the fruit and irregular irrigation can lead to blossom end rot. Harvesting paprika Your paprika peppers are ready to harvest when they develop full color. Since different varieties are different colors, you need to read that seed packet or plant label. And don’t let the colors fool you. Reddish paprika peppers are more mild, while the brown and yellow paprikas are hotter.  Yellow paprika peppers (matthiasboeckel) needpix.com Preparing your paprika Depending on whether you prefer sweet or hot paprika, you may want to incorporate those other, hotter peppers, or remove most of the seeds and pith for a sweeter paprika. In either case, the peppers must be thoroughly dried. You can use a thread and needle to string your paprika peppers up to dry.  Peppers strung up to dry (OpenClipart-Vectors) Pixabay
Did you know that paprika peppers contain more Vitamin C than lemon juice and that their flavor improves when heated?
Now you know. If you have a large, lovely, and productive avocado tree, you will want to be sure to prevent avocado root rot. This disease is commonly caused by overwatering and it is usually fatal to the tree. [By the way, removing large trees is expensive and dangerous.]  Gallberry plant infected with avocado root rot (Elizabeth Bush, Virginia Polytechnic Institute and State University, Bugwood.org) CC BY-SA 3.0 Avocado root rot is perhaps the most common disease of California’s avocado orchards, but nearly all fruit and nut trees are susceptible, as are azaleas, blueberries, boxwood, camellias, cinnamon trees, conifers, cycads, ferns, lilies, mosses, pineapples, and roses. Avocado root rot also threatens California’s rare endemic Ione manzanita (Arctostaphylos myrtifolia). What causes avocado root rot? Large trees and shrubs use a lot of water. Adding too much water creates habitat for tiny water molds, called oomycetes. Oomycetes are responsible for Phytophthora [Fie-TOF-ther-uh] root and crown rot diseases. This is one of those. The oomycete responsible for avocado root rot is called Phytophthora cinnamomi. The Global Invasive Species Database includes Phytophthora cinnamomi in its list of "100 of the World's Worst Invasive Alien Species". These water molds were originally found only in tropical and subtropical countries. They are now found around the world. Water molds fall between fungi and algae. They fly through the air and exist in waterways and the soil. Normally, they are not a problem. Until environmental conditions are suitable, the oomycetes that cause avocado root rot mostly remain dormant in the soil. Add too much water and spores germinate, producing mycelia or hyphae (tiny vegetative threads) and sporangia (reproductive parts). The sporangia release spores that are small enough to enter a root through the root tip. Once they enter the root, they start absorbing nutrients and carbohydrates, breaking down the root structure and preventing the plant from absorbing water and nutrients.  Roots infected with avocado root rot. Note the lack of short lateral roots and presence of black, necrotic and sloughing cortical tissues. (Edward L. Barnard, Florida Department of Agriculture and Consumer Services, Bugwood.org) CC BY-SA 3.0 Symptoms of avocado root rot The most common symptom of avocado root rot, or Phytophthora dieback, is wilting. This is a problem because many people respond to plant wilting by adding more water, which is what caused the problem in the first place. Other symptoms include brown edges on leaves, chlorosis (yellowing), collar rot, darkened patches of bark and root tissue, gumming, leaf curl, reduced fruit size, stem cankers, and young shoot dieback. Flagging may also be seen. Flagging refers to the way dead leaves are retained by the plant, rather than allowed to fall.
Preventing avocado root rot Proper tree planting depth is the best thing you can do to keep your trees healthy. Other preventive measures include:
Commercial orchards infected with avocado root rot may inject or spray affected trees with fungicides, or resort to soil solarization. These are extreme measures that should be avoided by the home gardener unless absolutely necessary. One thing you can do is cover the area with composted mulch, which suppresses the oomycetes that cause the disease and prevent healthy trees from becoming infected. Or, you can get a load of free arborist chips which will, eventually, compost themselves, preventing disease and improving soil structure. Our story When we bought our place back in 2012, there was a lovely old apricot tree in the backyard. She wasn’t performing very well, however. Upon closer inspection, the tree seemed a little “loose” in the ground. When I gave it a shove, the whole thing fell over! The root system was practically gone. Luckily, the tree had been kept at a manageable size and no one was hurt. I decided to use the trunk to create a stumpery and plant a new apricot tree. We later learned that the sprinkler system was pointed directly at the tree, creating a recipe for disaster.
While you may not be able to eliminate the oomycetes that cause avocado root rot from your property, you can control the conditions that allow them to cause harm.
Foliar feeding refers to feeding plants by spraying nutrients on leaves and fruit.  Spraying nutrients on seedlings (mayapujiati) Needpix Normally, plants absorb their mineral nutrients from the surrounding soil through the root system. Nutrients can also be absorbed through the stomata, tiny holes used for gas and moisture regulation, found on leaves and fruit. Foliar feeding claims Advertisements claim that foliar feeding is many times more efficient than soil feeding, that it cannot be used incorrectly, it promotes larger, sweeter crops, boosts a plant’s tolerance for heat and cold, increases pest and disease resistance, and even improves a plant’s internal circulation. Wouldn’t that be something? The number and diversity of these claims should raise a warning flag, and with good reason. Most of the claims about foliar feeding are false, but there are situations where foliar feeding is useful. Foliar feeding research The claims made about foliar feeding are based on research published in 1957 in which leaves and fruit were shown to be very efficient at absorbing tiny amounts of mineral nutrients in a lab setting. You can read the full report here. Unlike nutrients absorbed through the root system and transported through the xylem, nutrients absorbed through leaf stomata are more likely to remain in nearby plant tissue. This is especially true for the ‘immobile’ nutrients, such as calcium and magnesium. According to the study, “Phosphorus, choline, sulfur, zinc, copper, manganese, iron, and molybdenum were intermediate [with regards to absorption] with decreasing mobility in the order given.” Potassium and sodium were shown to be the most readily absorbed and highly mobile nutrients.  Stomata in a tomato leaf shown via colorized scanning electron microscope image (Photohound) Public Domain Again, this research was conducted under laboratory conditions, not out in someone’s garden. As one might expect, results are very different in the field. There are, however, some cases where foliar feeding is a good thing. Foliar feeding and alkaline soil Nutrient absorption is helped or hindered by soil chemistry and electrical charges in the soil. One aspect of that chemistry is soil pH. Acidic soil has a pH of less than 7.0 and alkaline soil has a pH greater than 7.0. This is important because alkaline soil is slower to release metallic nutrients, such as iron and manganese. If your soil is deficient in these nutrients, foliar feeding can help in the short-term while you make long-term adjustments to your soil. The downside to foliar feeding Simply spraying fertilizer on your plants’ leaves is a good way to burn them. There are too many variables to make foliar feeding something you would want to do all the time with all your plants. Environmental conditions, species characteristics, developmental stages of the plants, varying thicknesses of plant cuticles, and the likelihood of stomata being open or not all contribute to a lot of wasted fertilizer and the potential for harm. Foliar feeding case in point For those of you who have been reading The Daily Garden for a while now, you may recall reading about how my first soil test, in 2015, reported extraordinary numbers for all nutrients except iron. This was due to over-fertilizing done by the previous owner. That imbalance made those abundant nutrients largely unavailable to my plants. Also, my soil pH at that time was 7.7 and the soil was badly compacted. Truth be told, it looked and felt like concrete. At that time, nearly all the plants in my landscape were being damaged by fungal diseases (partly due to badly aimed sprinklers), aphids, borers, scale insects, and what looked like nutrient deficiencies. Of course, the automatic (and incorrect) response would have been to add more fertilizer. Thanks to my lab-based soil test, I had the information I needed to make better decisions.
This brings me to the most important aspect of foliar feeding: it is a temporary fix for a much larger soil problem.
Instead, select plants suited to your soil and microclimate, get your soil tested periodically, and remain skeptical about too-good-to-be-true advertisements. Measles on fruit, leaves, or stems can mean many different things, but it is definitely not the human measles virus.  Apple exhibiting measles from manganese toxicity University of Georgia Plant Pathology , University of Georgia, Bugwood.org CC BY-SA 3.0 Grape measles If it looks as though your grapes have the measles, it may be black measles, also known as esca or Spanish measles. Grapes infected with black measles develop small, reddish-brown spots on the fruit. These spots may appear at any time during the growing season and will ultimately cover the fruit, causing it to turn black and shrivel up. If you were to eat these grapes, they would taste bitter. Leaves develop a characteristics ‘tiger stripe’ pattern in which the veins of white grapes remain green, haloed with yellow, and surrounded with dead, brown tissue, while red or purple cultivars develop a reddish area, instead of yellow. Other symptoms include shoot tip dieback and complete defoliation. Also, cut wood tends to ooze a dark sap and cross-sections show dark streaking in the xylem. Infected plants are highly susceptible to other fungal diseases, particularly rots. #/media/File:ESCA_Blattsymptom_1.JPG) Leaves infected with grape measles (Bauer Karl) CC BY 3.0 at Measles on plants can indicate fungal diseases that may look like anthracnose. Measles can also indicate nutrient toxicities or an overabundance of irrigation water. Black measles are caused by a collection of fungi: Phaeoacremonium aleophilum and other subspecies, Phaeomoniella chlamydospora, and Fomitiporia mediterranea. Fungal spores enter plants through pruning wounds and natural cracks in the bark. Symptoms do not appear every year and seem to be worse in years with heavy rains. When a particularly bad measles infection occurs, it is called an ‘apoplexy’. Apoplexy is nearly always fatal. There are no effective treatments against esca, other than removing infected fruit and crossing your fingers. Otherwise, remove the plant and start over. While there are no immunizations against plant measles, providing good air flow and making sure that your cutting tools are clean and sanitized will go a long way toward protecting your plants against measles. Also, make sure you get your bare root stock and/or scions from reputable sources. Measles as a symptom of nutrient toxicity Measles can also indicate a nutrient toxicity. Brown freckles on apple or pear fruit may simply be a characteristic of the cultivar, or it may indicate that there are toxic levels of manganese in the soil. Apple measles on tree bark looks like round to oval concentric circles or lesions. The only way to know if there are toxic levels of nutrients (or heavy metals) in your soil is with a lab-based soil test.  Bark measles on an apple tree (William M. Brown Jr., Bugwood.org) CC BY-SA 3.0 Measles and irrigation Smooth-skinned cucurbits, such as crookneck squash, cucumbers, summer squash, melons, and pumpkins are all susceptible to an entirely different set of measles. Small brown spots, similar to those seen on grapes infected with esca, may be seen scattered over the surface, but this discoloration does not penetrate the fruit. These spots may also occur on leaves and stems. Unlike the viral infections and nutritional toxicities mentioned above, cucurbit measles are a physiological response to high soil moisture. When plants absorb too much water, they ‘sweat’ it out in a process called guttation. Guttation often carries salts along with water. Those salts collect where the guttation droplets are deposited. The salts burn the epidermis of the plant, causing a discoloration known as measles. Cucurbit measles can be avoided by watering less often and more deeply, especially as fruits reach maturity.  Guttation on water horsetail (Luc Viatour) CC BY-SA 3.0 If you see measles in your garden, take a closer look to see if it is something you can fix.
Cherimoya, or custard apple, is a creamy, tropical fruit that you may be able to grow for yourself.  Cherimoya fruit (Maya A. P.) Pixabay According to Mark Twain, cherimoya is “the pride of the [Hawaiian] islands, the most delicious fruit known to men.” He went on to explain that cherimoya has a soft pulp that is eaten with a spoon. Many describe the fruit as tasting similar to pears, but creamier and better. These fruits do not ship or store well, which is why you rarely, if ever, see them in stores. Cherimoya are often considered one of the three best fruits in the world.  Interior of cherimoya fruit (Hannes Grobe) CC BY-SA Cherimoya description Cherimoya is a fast-growing, dense tropical tree or shrub with a relatively small root system. Trees range from 16 to 30 feet in height. Grown outside of their traditional range of the Andes, Bolivia, and Peru, these evergreen trees may become briefly deciduous. Leaves are dark green and glossy with large veins and can be up to 9” long. Stems and young branches are covered with rust-colored hairs. Leaves may also have these hairs.  Beetle on cherimoya flower (Marcelo RosaMelo) Public Domain The small, fleshy green and occasionally pink flowers are unique in that they bloom first as female flowers and a second time as male, lasting only two days. The petals of female flowers are held tightly together, while male flower petals open widely. Cherimoya seeds are black, glossy, bean-like, and poisonous, so don’t eat them.  Cherimoya seeds (Badagnani) CC BY 3.0 Cherimoya fruits average 1 to 2 pounds, but they can weigh 5 pounds or more.They may be oval, conical, or somewhat heart-shaped and up to 8” across. The flesh is white, fragrant, and delicious. Cherimoya skin The skin of a cherimoya fruit may be green our brown when ripe. Ripe green-skinned cherimoya are described as having a texture similar to pears or papayas. Ripe brown-skinned cherimoya have a texture and flavor similar to custard. The problem is, brown skin can also mean the fruit has gone bad and started to rot, or that it spent too much time in the refrigerator. Cherimoyas are classified according to the degree of skin irregularity. Many varieties exhibit scale-like structures, called areoles:
How to grow cherimoya Cherimoya (Annona cherimola) can be grown in U.S. Hardiness Zones 9-11, as well as Sunset zones 18 through 24. These trees prefer higher elevations, hot, sunny days and cool, moist nights. Cherimoya trees grow best in acidic soil with a pH of 5.0 to 6.5 and good drainage. You should place your cherimoya tree where it will be protected from strong winds and scorching summer days. Most cherimoya trees are purchased as grafted bare root stock. A hole should be dug wide enough for the roots to spread out, but no deeper than is needed to cover those roots. Proper tree planting depth keeps the graft and crown above ground. Do not tamp down the soil. Instead, mud in your new tree to get rid of air pockets and to provide the water it needs. As your cherimoya tree is actively growing, it should be watered regularly. Do not irrigate your cherimoya while it is dormant. Cherimoya trees perform best if they receive a balanced fertilizer, such as 8-8-8, every three months, starting in the middle of winter.  Cherimoya fruit on stem (Marcelo RosaMelo) Public Domain Cherimoya fruit is heavy, so it is important to train your cherimoya tree to have strong branches. Each year, two-thirds of the previous year’s growth should be removed, along with any dead, diseased, or rubbing branches. Generally speaking, only those branches that emerge at a 60° angle from the trunk are retained. These fast-growing trees can easily be espaliered. Cherimoya pollination Like avocados, the flowers are hermaphroditic. They open as females on the first morning, close up for the night, and reopen later the second day as male. Because cherimoya trees are native to South America, most of our northern pollinators do not recognize cherimoya blossoms. It is believed that a certain tiny beetle pollinates native cherimoya flowers. Cherimoya flowers also have mechanisms that prevent self-pollination. This means you may need to hand-pollinate your cherimoya flowers to obtain any fruit. Don’t worry, hand-pollinating is easy. Simply take a male flower and touch its anther to the pistil of a female flower. This may need to be done several times but, for a 5-pound fruit, it sounds like a good trade! Cherimoya pests and diseases Cherimoya is generally disease-free, though it can become infected with Armillaria root rot, Verticillium wilt, and crown rot. Ants and mealybugs will cause the most problems, followed by Abbot’s bagworm moth (Oiketicus kubeyi), Conchaspis angraeci scale, fruit flies, hairstreak butterfly caterpillars (Thecla), leaf miners, seed borers, and thrips. Seeds are often infested with weevils. If you live where a cherimoya tree can grow, you owe it to yourself and your family to give it a try. Creating a sun map of your yard may surprise you. And your plants will thank you.
Sun-loving tomatoes will never produce abundant fruit if they don’t get enough sunlight, while tender lettuces may bolt before producing much in the way of salad greens if they get too much sunlight. Without enough sunlight, plants die. Without the right type of sunlight, plants fail to thrive. Just as a soil map can help you take better care of your plants, creating a sun map of your yard will help you see where different types of sun exposure occur at different times of the year. This will help you place plants where they can grow and thrive. How to make a sun map Making a sun map of your yard is not hard, but it does take some time - a full year, in fact. That’s because the angle of the sun changes from season to season and you will need information from each season to make an accurate sun map. The easiest way to create a sun map is to start by taking photos in the morning, midday, afternoon, and early evening in each of the four seasons. To make this job easy to remember, you might want to set aside the spring and autumn equinoxes and the summer and winter solstices for this task. If you aren’t that motivated, you can do it in spring and summer. Select viewpoints that give you the widest perspective on your property. You might want to position a lawn chair, plant stake, or other marker at each of your shooting spots so that they remain consistent, but this isn’t necessary. The important thing is to get out there and take the photos. To put those photos to work, you can use graphics layering software (beyond me), you can draw a sketch of your property, or use a printed Google Maps screenshot of a terrain view of your property. I start with the terrain view and then trace the image. These images are very handy, I keep copies in my file cabinet. The next step is to decide on a key for each type of sun exposure.
Sun exposure Morning sunlight and afternoon sunlight are different. Sunlight in summer and winter are different, too. Sun exposure is classified this way:
These terms do not give you a ton of information, but they give you enough to make better decisions about where you grow your plants. Your key will use different symbols to indicate different types of sun exposure. For example, your key may use dots for full sun, dashes for partial sun, slashes for partial shade, and tiny triangles for full shade. Take your property map and your photos and pencil in the different sun exposures, using your key. For more helpful information, use different colored pencils for each season. This will help you see how things change over the course of the year. Or, you may prefer creating a different sun map for each season and saving the colored pencils for the different sun exposures. How you do it doesn't matter. That you do it does matter.
Why map the sun? The most important benefit of a sun map is that it helps you position plants, raised beds, and structures, such as garden sheds, properly in the first place. If everything is already in place, a sun map will help you select the best locations for annual plants. A sun map can also help you figure out why fungal diseases may keep occurring in certain areas. Locating plants prone to fungal disease in areas where they will receive morning’s first light will help dry leaves as quickly as possible. And if your summers are like mine, you can reduce the afternoon scorch by locating plants where they will receive some protection in the afternoon.
Sunlight calculators
Retailers are happy to sell you a physical sunlight calculator and apps for your phone, but these are not useful. You can see for yourself if an area is shaded or not. Much like OTC soil tests, the information these products provide is not detailed enough to actually mean anything. It is all too easy to forget about the effect of seasons on sun exposure. As neighboring trees leaf out or drop their leaves, nearby plants can find themselves in a completely new environment in a short period of time. Creating a sun map may also give you a better view on how your plant population changes over the seasons. It's pretty amazing stuff! You’ve seen the words, but what do partial sun and partial shade mean? Are they the same thing? Sun exposure is an important part of knowing where to put your plants.  Sunlight through leaf canopy onto small white flowers (Pexels) Without sunlight, most plants can’t grow. Plant labels and plant descriptions often give you information about the amount and intensity of sunlight a plant needs, but the terms can be a little confusing. Some yards receive more sunlight than others. Knowing how much sunlight an area gets can help you select the right plants for that space. Keep in mind that some plants can grow in more than one type of sun exposure. Full Sun Full sun means 6 to 8 hours of direct sunlight every day. Full sun is usually found on the south side of your house (assuming you live in the northern hemisphere). Full sun plants are your go-getters. Most summer crops prefer full sun. Artichokes, cucumbers, eggplant, fruit and nut trees, peppers, squash, tomatoes, and most herbs need 8 to 10 hours of direct sunlight each day. Plants with silver or gray foliage also prefer full sun.  A south-facing wall and a ladder support give pumpkins plenty of sunlight (Kate Russell) Partial Sun Partial sun means 3 to 6 hours of sunlight in the afternoon. Partial sun is usually found on the west side of your house. We can call these the late sleepers of the plant world. They need time to wake up and may not be ready to deal with sunlight until later in the day. Artichokes, asparagus, beans, beets, blackberries, broccoli, cabbage, carrots, cauliflower, chives, leeks, cilantro, garlic, kale, lettuce, melons, mint, onions, oregano, peas, potatoes, radishes, raspberries, rutabagas, Swiss chard, and turnips can be grown in partial sun.  Wax beans prefer partial sun (Kate Russell) Partial Shade Partial shade means 3 to 6 hours of morning sun with protection from more intense midday and afternoon sun. These are your early risers. Artichokes, arugula, asparagus, beans, blackberries, bok choy, Brussels sprouts, cauliflower, endive, garlic, kale, lettuce, mustard greens, onions, radishes, raspberries, spinach, and Swiss chard grow well in partial shade.  Containerized arugula grows well on a patio protected with a pergola (Kate Russell)
Before you start sticking plants in the ground, you should probably create a sun map of your yard. This will tell you how much sunlight each area actually gets. And remember, those areas change with the seasons. Also, the plants themselves can create different degrees of shade or exposure for other plants. I grow chives under my artichoke plant. This is a form of companion planting, or intercropping.
If you have a garden with traditional rows, your plants will get the most sun exposure if your rows are oriented in north-south directions and your tallest plants are at the northern end of your garden plot. Native to boreal and arctic forests, lingonberries are close cousins to cranberries.  Lingonberries growing in Sweden (Jonas Bersten) Public Domain Used to make jam, syrup, and sauce, lingonberries are very tart, tasting like a cross between cranberries and raspberries. Lingonberries (Vaccinium vitis-idaea) are also known as cowberries, mountain cranberries, partridgeberries, cougarberries, beaverberries, and several other animal-berry combinations, depending on where they are found. Lingonberry description Lingonberries are tough, short evergreen shrubs. They rarely grow more than 18” in height. Plants produce white to pink bell-shaped flowers and bright red edible berries. Broad, oval leaves grow alternately along rounded stems. Unlike most broadleaf plants, lingonberries retain their leaves all year. Fruit is bitter early in the season but sweetens somewhat through winter. Even at its sweetest, lingonberries are very tart. .jpg) Lingonberry flowers (Hans Hillewaert) CC BY-SA 3.0 Plants spread out using underground stems, called rhizomes. Lingonberry plants are self-pollinating, but crops are larger and ripen earlier when more than one plant is nearby. Each plant blooms twice a year, creating the potential for two crops. Flowers are not frost-hardy, so the first crop is often lost to a late frost, but these tiny shrubs are very prolific. Lingonberry species There are two regional subspecies of lingonberry. The Eurasian lingonberry (V. vitis-idaea subsp. vitis-idaea) has larger leaves that can be more than 1” long. The North American lingonberry (V. vitis-idaea var. minus) has much smaller leaves, usually less than 1/2” long.  North American lingonberry fruit growing in Alaska (Dawn Endico) CC BY-SA 2.0 Sadly, some North American populations and subspecies of lingonberry are now in trouble. Specifically, the Michigan lingonberry is endangered and the Connecticut lingonberry is believed to be extinct. How to grow lingonberries Lingonberry plants need cold weather and good drainage. They can tolerate temperatures as low as -40°F but cannot grow well in areas with hot summers. Lingonberries grow best in moist, acidic soils (pH 4.2-5.2) under the type of shade one would find under a forest canopy. [That certainly rules out my yard.] If you live in U.S. Hardiness Zones 3-8, you can grow your own lingonberries. Most people start with potted seedlings from a reputable supplier. You can also grow lingonberries from cuttings or divided roots. Just remember to place live plants in quarantine before adding them to your landscape. At planting time, dig a hole that is large enough to allow the roots to spread out, making sure that the planting depth remains the same. You don’t want to bury the crown or stem. Plants should be spaced 12” apart. Do not tamp down the soil. Instead, mud in your new plants. This will protect the delicate root hairs that plants need to take up water and nutrients.  Flowers and young shoots of lingonberry (Miya.m) CC BY-SA 3.0 Weeds are the biggest threat to your lingonberry plants. A thick mulch of wood chips around the plants can reduce that problem and improve soil structure, help retain moisture, and eventually add nutrients to the soil. Your lingonberries will not require much in the way of fertilizer. In fact, adding too much nitrogen increases the odds of your plant dying in winter. A better choice would be to top dress around your lingonberry plants with a little bit of aged compost or fish emulsion and leave them be. You can also use a complete fertilizer, such as 5-10-5 each spring.
Lingonberries perform well in raised beds and containers. You should protect your lingonberry plants from severe winds. Lingonberry plants are sensitive to chlorides, which means your need to keep them away from chlorinated pool water, de-icing salts, and fertilizers containing potassium chloride. Lingonberry pests and diseases Birds, bears, and foxes love lingonberries. So do aphids, armyworms, mealybugs, and whiteflies. Bacterial leaf spot and grey mold may occur, but these diseases can often be prevented by not watering from above. Instead, use soaker hoses or furrow irrigation to keep water off the leaves. Not everyone lives where lingonberries grow. If you do, you owe it to yourself to give them a try.  Ripening red gooseberries (GLady) Pixabay Native to Europe, gooseberries are now commonly found in North America. Cousin to currants and jostaberries (a cross between currants and gooseberries), gooseberries can be eaten fresh or used to make delicious pies, jams, and jellies. Gooseberry flowers also attract many pollinators and other beneficial insects.  Gooseberry flower (pxhere) Public Domain Gooseberry description Gooseberries (Ribes uva-crispa also R. grossularia) grow on bushes that can reach 5 feet in height and width. These shrubs have spiny branches and stems that can make working with them a little tricky. Berries can be hairy or smooth, much like peaches and nectarines. They are usually green, but can also be white, yellow, or a reddish-purple. Gooseberries are categorized as culinary or dessert varieties.  Gooseberries (Kornelia und Hartmut Häfele) CC BY-SA 3.0 How to grow gooseberries Gooseberries grow best in U.S. Hardiness Zones 3 to 8, but can be grown in shaded areas in regions with warmer summers. Gooseberries are self-pollinating, so you only need one. Gooseberries can be propagated from seed or cuttings. You may also find them available as bare root stock. Gooseberries can be planted from late fall through early spring. Caring for gooseberries Gooseberries perform best when pruned for good airflow. This is best done in winter, while the plant is dormant. Gooseberries can be trained along a fence or up a trellis. This also makes it easier on your arms when harvesting. They can also be grown in large containers. When pruning gooseberries, start by removing any dead, diseased, or rubbing branches and any suckers. Then prune to reduce crowding. Finally, prune back any remaining growth by one-half. Lateral branches should also be cut back, leaving one to three buds. Being native to alpine regions and other areas with poor soil, providing gooseberry plants with extra nitrogen often results in too much vegetative growth. This means you get less berries and more spindly branches. Gooseberries should be given a top dressing of aged compost at the end of each winter to help them grow in spring. Mulching around gooseberry plants will also help reduce weeds and stabilize soil temperatures. Both because of the spines and the need for significant pruning, heavily laden branches should be removed completely, once the fruit is ripe. This allows light to reach new growth next year. .jpg) Red gooseberries (Darkone) CC BY-SA 2.5 Gooseberry pests and diseases
Gooseberry plants are susceptible to several fungal diseases, such as American gooseberry mildew, anthracnose, currant cane blight, grey mold, and septoria leaf spot, so avoid overhead watering and be sure to provide good drainage. In North America, gooseberry sawflies (Nematus ribesii), also known as currant sawflies and imported currantworms, are the most common pest. Aphids, brown marmorated stink bugs, currant borers, gooseberry fruitworms, and clearwing moths may also cause problems. And birds. Note: If you live in New Hampshire, North Carolina, or West Virginia, you are not allowed to grow gooseberries or other Ribes plants. If you live in Massachusetts, New Jersey, Rhode Island or Delaware, you’ll need a permit. These bans are in place because Ribes can carry white pine blister, an imported Asian rust fungus that has devastated high elevation pine forests. Thanks to reader Carol Peck, I learned that California hosts several native edible gooseberry varieties. These include canyon gooseberry (Ribes menziesii), flowering gooseberry (R. speciosum), hillside gooseberry (R. californicum), Santa Lucia gooseberry (R. sericeum), Sierra gooseberry (R. roeslii), spreading gooseberry (R. divaricatum), and yellow gooseberry (R. quercetorum). Thanks to Carol Peck for the information! If you are lucky enough to live where you can grow gooseberries, give them a try. These shrubs are very prolific and the fruit is delicious! Mizuna is a tasty Asian green that you can grow in containers, on a windowsill, or in your garden.  Mizuna greens (Masahiko Satoh) CC BY 2.0 With its slightly peppery flavor, similar to arugula, it should come as no surprise that mizuna is part of the cabbage family. Young leaves are used raw, in salads, and mature leaves are lightly cooked in stir-fry and soups. Flowering stems can also be cooked the same ways you might cook broccoli. In Japan, mizuna is also pickled. Mizuna (Brassica rapa var. niposinica), also known as Japanese mustard, water greens, or spider mustard, is cousin to bok choy, mustard, Napa cabbage, ruby streaks, and turnips. Mizuna is a great addition to salad gardens and stir-fry gardens. It can be grown outdoors in U.S. Hardiness Zones 4 to 9. Mizuna description This cool season crop looks as good as it tastes. Mizuna grows in a mounding rosette that can be up to 9” high and 18” across. The glossy green leaves are feathery and serrated. Stems are pale green to white. Some specialty varieties even have purple stems! Mizuna flowers look like those of most other cruciferous plants with four yellow petals. Mizuna is a biennial, which means it generally goes to seed in its second year. How to grow mizuna Mizuna grows easily from seed. You can start seeds in pots and then transplant seedlings, or sow seeds directly in the ground. In either case, seeds should be covered with 1/4” of soil or vermiculite. Plants grown to be used while young should be spaced 4” to 6” apart, plants grown for “cut and come again” harvesting should be planted 8” apart, and plants destined to be harvested when mature should be spaced 12” to 16” apart. Keep the soil moist until germination occurs and then water frequently, allowing the soil to dry out between waterings. Mizuna plants can be grown in full sun or partial shade, as long as they get at least 3 to 4 hours of sunlight each day. They prefer loose, nutrient-rich soil, so you may want to band the area with aged manure or compost at planting time and top dress with fish emulsion or more compost throughout the growing season. Banding refers to incorporating fertilizer or other nutrient sources into the soil on either side of seeds at planting time. Mizuna grows best in soil with a pH of 6.0 to 7.5. Succession planting can extend your harvest throughout the cooler months. Mizuna will bolt as temperatures rise. If you allow it to go to seed, you will be providing local pollinators and other beneficial insects with pollen and nectar, plus you will get seeds for future crops. Mizuna pests and diseases Flea beetles and slugs and snails will pose the biggest threat to your mizuna crop. Aphids and whiteflies may also try feeding on your mizuna. Mizuna is not disease-prone.  Mizuna growing on the International Space Station (NASA) Public Domain Salad burnet leaves may look like parsley or celery, but this cucumber-flavored perennial is actually a member of the rose family, along with nectarines and blackberries.  Salad burnet plant (Archenzo) CC BY-SA 3.0 If that weren’t surprising enough, its edible young leaves make great additions to salads, sandwiches, dressings, eggs, soups, iced tea, and Bloody Mary’s. This fragrant, mounding, evergreen herb produces stunning red to purple apetalous* flowers in summer. And it is practically pest- and disease-free! I don’t know why we don’t see salad burnet in stores, but we can grow our own at home. *Apetalous means 'without petals'.  Salad burnet apetalous flower (Ian Lindsay) Pixabay How salad burnet grows Salad burnet (Sanguisorba minor), also known as garden burnet, salad burnet, small burnet, or simply burnet is a drought- and frost-tolerant plant that grows best in U.S. Hardiness Zones 4 to 8. It has a low-growing rosette shape that may reach 6” to 18” in height. Salad burnet is a short-lived perennial that is often grown as an annual. Leaves are pinnate and toothed. How to grow salad burnet Salad burnet grows best in loose soil with good drainage. It prefers a soil pH of 6.8, though it is a tolerant plant. In most regions, salad burnet should be planted in full sun. In hot regions, dappled sun is better. Start seeds in pots filled loosely with potting soil. Only lightly cover seeds with soil (no more than 1/8”) and keep the soil moist until germination occurs. This should take 1 to 2 weeks. [Note: to prevent seeds from being flooded into a corner of the pot, thoroughly water the soil before planting, then cover seeds with vermiculite or just a little soil and then use a mister to keep the soil moist.]
Salad burnet prefers moist soil, so you may want to consider planting it near a hose spigot or next to a rain gutter. Mulching around plants will help reduce weeds, retain moisture, and stabilize soil temperatures. Top dressing every 6 weeks or so with aged compost or feeding with fish emulsion will help keep your salad burnet plant productive and healthy. You may want to remove flowering stems to encourage more leaf growth, but the apetalous flowers really are stunning.  Salad burnet flower with seeds (Reinhold Möller) CC BY-SA 4.0 Harvesting salad burnet
Dried salad burnet does not retain its flavor, so you will want to snip off young leaves as they are needed. The more you take the more the plant will produce, as long as you don’t take more than one-third of the plant at a time. You can also freeze leaves in ice cubes for later use in beverages or hot dishes. Older leaves tend to taste bitter so should be tossed to the compost pile. Salad burnet is predominantly pest-free. The only disease I could find that affects salad burnet is leaf spot. Add salad burnet to your herb garden, storybook garden, or grow it on your windowsill. Yellow crookneck squash offers a sweet, buttery harvest and they are easy to grow  Yellow crookneck squash (Mike Goad) Pixabay Yellow crookneck is an annual summer squash, close cousin to zucchini, straightneck, and scallop squash. Yellow crookneck squash plants Yellow crookneck squash plants have very large leaves with bristles on the underside. The stems are tubular and also have bristles. Each plant may take up 3 to 4 square feet. The fruit is bright yellow (making it easy to find, come harvest time) with thin skin that may be smooth or bumpy and a hook at the stem end. Yellow squashes without the hook are called straightneck.  Crookneck yellow squash plant (Sheila Brown) needpix.com Unlike squashes and melons that spread vines around above ground, yellow crookneck squash are bushes that do their spreading in the soil. They have taproots, which may go down 30”, but the overall root systems are shallow and may spread out 2 to 4 feet in all directions. Squash plants produce both male and female flowers. The males flowers emerge first. Scientists believe this is to attract pollinators. Squash is not self-pollinating, so you will want bees, wasps, and other pollinators to come visit. You can boost those odds by planting shallow, bright white, yellow, or blue flowers, such as borage, lavender, nasturtiums, pot marigold, salvia, sweet alyssum, or zinnias nearby.  Squash bees pollinating female summer squash flower (USDA) Public Domain  Male summer squash flower (USDA) Public Domain How to grow yellow crookneck squash
Like other cucurbits, yellow crookneck squash prefers a sunny location with loose, well-drained soil and a soil pH of 5.8 to 6.8. If you are like me, the only one of those available in abundance is summer sunlight. Over time, you can acidify alkaline soil and improve soil structure with a mulch of arborist chips, but these things take time. If you’d rather not wait that long, raised beds or large containers are good options. Once temperatures stay at or above 60°F, seeds can be planted 2” deep and 3 to 4 feet apart, if planting in rows. Another option is to create hills that are 6” to 12” tall and 20” across. In each hill, plant 4 or 5 seeds, spread 3” apart, and keep only the best seedling for each hill, snipping off the others at soil level. In arid regions, you can use inverted hills, or shallow areas. This makes watering easier, but it may increase problems with pests and fungal disease. Fruit production should start 60 days after planting. If your plants are not producing, use a moisture meter to make sure they are getting enough water. Those big leaves may droop in the afternoon, but if they haven’t perked up by morning, they need more water. You can protect fruits from pests and disease by placing straw around the plant. This keeps fruit off the ground, preventing a case of measles, and it helps stabilize soil temperatures. Squash plants are heavy feeders. You can help them stay healthy and productive by top dressing around plants with aged compost or fish emulsion. Avoid applying extra nitrogen. Nitrogen stimulates leaf growth, not fruit. Harvesting yellow crookneck squash Fruits are produced near the base of the plant and should be harvested when they are 4” to 7” long and 2” in diameter. Like other summer squashes, yellow crookneck squash will get tough is allowed to grow too large. Harvesting frequently also spurs the plant to produce more fruit. Just be sure to cut fruit from the plant with a clean knife. Do not twist fruit off as this can damage the plant, making it easier for pests and diseases to get inside. While male squash flowers are edible, they are commonly battered and deep-fried, harvesting the flowers can significantly reduce your crop. If you keep harvesting, these plants will keep producing. Squash can be cubed or spiralized, blanched, and frozen for later use, or used in chutney and relishes. Because squash is a low-acid food, it cannot be safely canned on its own. Even using a pressure canner to preserve summer squash is no longer considered adequate. Yellow crookneck squash pests and diseases If you see a small hole in the stem of your squash plant, slit the stem open further to see if the problem is squash vine borers. Borers can be removed by hand and then the stem laid on the ground and covered with soil. If you’re lucky, new roots will develop at the cut. Other pests include armyworms, cabbage loopers, crickets and grasshoppers, cucumber beetles, cutworms, darkling beetles, dried fruit beetles, earwigs, false chinch bugs, flea beetles, green peach aphids, leafhoppers, leaf miners, melon aphids, seed corn maggots, spider mites, squash bugs, stink bugs, thrips, whiteflies, and wireworms. If you live in the southeastern U.S., melonworm moths and pickleworms may also be a problem. Irregular irrigation can reduce fruit production and lead to blossom end rot. Fungal diseases, such as anthracnose, charcoal rot, damping-off, downy mildews, Fusarium crown and foot rot, Fusarium wilt, Phytophthora fruit and crown rot, powdery mildew, sudden wilt, and Verticillium wilt. Bacterial diseases of summer squash include angular leafspot, bacterial leaf blotch, and bacterial wilt. Squash plants are also susceptible to viral diseases, such as cucumber mosaic, cucurbit aphid-borne yellows, cucurbit yellow stunting disorder, curly top, potyviruses, and squash mosaic virus. Most of these diseases can be prevented by installing clean, disease-free seed, selecting resistant varieties, spacing plants for good airflow, and by avoiding overhead watering. If you keep leaves dry and do not handle plants while they are wet, the spread of pathogens is significantly reduced. Diseased plants should be removed and discarded. Despite all those threats, yellow crookneck squash plants are impressive and productive. You probably only need two of these plants to keep your family supplied. If all that weren’t enough, molybdenum deficiencies can cause a condition known as yellows. Yellows eliminates squash fruit set and generally kills the plant. [What does your soil test say about molybdenum in your garden?] As the growing season nears its end, leave one fruit to complete its life life cycle. You won’t want to eat it, but the seeds can be used for next year’s crop. And your chickens will be happy to take care of the scraps. Just be sure to keep different types of summer squashes away from each other. Cross-pollination doesn’t always result in desirable offspring. |
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