Small black spots on tomatoes and tomato leaves often indicate bacterial spot.
Those black spots might not look like anything important, but this bacterial disease can also affect peppers, eggplant, groundcherries, and tomatillos, along with your tomatoes. Close cousin to the bacterial spot of almonds and practically impossible to differentiate from bacterial speck without a microscope, bacterial spot (Xanthomonas campestris pv. vesicatoria ) is perfectly capable of killing your tomato plants.
Bacterial spot symptoms
Symptoms of bacterial spot can appear on all life stages, from seedlings to mature plants, and on all aboveground plant parts. Bacteria enter through wounds and stoma. Infected younger plants can be completed defoliated by bacterial spot. Older plants exhibit insignificant looking water-soaked areas on mature leaves, usually near the bottom of the plant. making it easier to dismiss this disease. This would be a mistake.
Closer inspection of these lesions shows that they start out yellow or light green, turning dark brown or black. Older spots may be raised areas that average 1/3” across. Larger damaged areas may be seen at the margins (leaf edges).
Immature fruit can also be affected by bacterial spot. Bacteria enter through tiny hairs, called trichomes. Infected areas start out looking like tiny raised black dots which then become sunken or dimpled, and surrounded by a white halo, similar to bacterial canker. The halos eventually disappear as the spots get larger and become scabby. These fruits, if they are able to mature at all without rotting on the vine, are still edible. Simply cut out the diseased areas. Just be sure to dispose of the infected parts in the trash. Do not add them to your compost pile.
Controlling bacterial spot
Because these bacteria overwinter in infected plant debris, you can protect next year’s crops by clearing infected plant tissue out of your garden completely each fall. The disease can also appear on volunteer tomato plants, so watch rogue tomato plants closely for signs of infection. Splashing rain, irrigation water, and contaminated tools can also spread the disease, so avoid overhead watering and be sure to sanitize your garden tools regularly.
Since these bacteria need humidity and water droplets to survive, pruning for good air flow can go a long way toward preventing this disease.
If you are like me and save seeds from each year’s crops, be sure you don’t use seeds from an infected plant, as you will be perpetuating the disease. As always, only buy certified disease-free plants and seeds and always quarantine new plants. Fixed copper sprays can be used in areas where bacterial spot has been a significant problem, although there have been some cases of copper-resistant bacteria. Crop rotation can also be used to break this disease triangle.
Protect next year’s crops by tossing plants infected with bacterial spot into the trash and providing good air flow around future plants.
Chayote is an edible gourd. These lumpy, green cousins to squash and pumpkins grow on perennial vines.
Also known as Buddha’s palm, chocho, mirliton, or sayote, chayote (Sechium edule) is a relatively bland, highly productive plant.
While chayote has been cultivated in Mexico and Central America since pre-Columbian times, archeologists have not been able to find any evidence of its existence back in those times. Apparently, chayote was not a food that lent itself to preservation.
Chayote fruit, roots, tubers, seeds, young leaves and stems are all edible. That being said, many people find raw chayote to be rather tough. In cooking, chayote is handled much like summer squashes, such as zucchini. Cooked chayote sprouts are very popular in many Asian dishes.
Chayote plants have thick roots and slender vining stems. Those vines can reach 30 feet in length. Fruits are oval and green, similar to pears, with deep wrinkles or ridges. When you slice a chayote open, you will find a large, flattened pit, similar to a mango seed.
Leaves are heart-shaped with three tips, and petioles (leaf stems) are grooved (sulcate) and 3” to 6” long. Tendrils occur along the stems. There are both male and female chayote flowers. Male flowers occur in clusters, while female chayote flowers are solitary.
How to grow chayote
You can start growing chayote with seeds or a chayote fruit. If using a fruit, allow it to sprout first, then lay it on its side and cover it with soil, leaving the sprout exposed. Personally, I like to get chayote seedlings from my local Master Gardeners’ fall plant sale.
Chayote is known as a short day plant. This means that flowering is not triggered until each day has less than 12 hours of daylight. In San Jose, California, that means chayote can be planted April through October.
These are sprawling plants that need a significant amount of room to grow, unless you train them up a trellis. Tendrils will grab hold of fencing, trees, a pergola, or cattle panels, lifting the fruit up off the ground. Similar to hops, chayote vines will grow as far upwards as they can, reaching 30’ to 36’ when a supporting wire or structure is available. While the vines can get quite long, your harvest will be better if vines are pruned back to a more manageable length. Plants should be spaced 7 to 11 feet apart.
Chayote can grow in full sun or partial shade. Fruits exposed to full sun will tend to be a light yellow color, while shaded fruits are a darker green. Before feeding your chayote plants, get a soil test to see what is already available. Chayote plants do not need a lot of nitrogen. In fact, too much nitrogen can cause flower drop (abscission).
After flowers have been pollinated, fruit will reach harvestable size in 1 - 2 months. Harvestable fruits are 4" to 6” in diameter.
Chayote pests and diseases
While these plants grow best in the rainy season, they do like soggy soil. Chayote needs good drainage to stay healthy. To offset the risk of root rot, plants are often installed in mounds or raised hills.
Being a member of the cucurbit family, chayote is subject to many of the same pests and diseases. Chayote diseases include downy mildews and certain tropical fungal diseases, most of which are not yet seen in North America.
Nematodes can be troublesome, as can chayote stem borers (Adetus fuscoapicalis), cucumber beetles, squash ladybugs, and squash vine borers.
While chayote is a perennial vine that can remain productive for up to 8 years, many pest and disease problems can be reduced or eliminated by replacing individual plants every 3 years.
Give these lovely vines a try in your garden this fall and let us know what it was like in the Comments!
The red juicy bits found inside a pomegranate are called arils. Arils are a type of accessory fruit, or false fruit.
True fruits and false fruits
Fruit is the tissue that surrounds the seeds of angiosperms (flowering plants). Fruit is made from a plant’s ovary. Except when it isn’t. In some cases, a fruit develops from both the ovary and nearby tissue. These tissues can be either the perianth (flower whorls) or the hypanthium (the flower base). When this occurs, the part we eat is called an accessory fruit, or false fruit. Common accessory fruits include figs, mulberries, pineapples, and strawberries. Arils are specialized versions of these false fruits.
Arils are outgrowths that cover seeds partially or fully, which may or may not turn in to an edible fruit. This outgrowth originates where the seed attaches to the ovary, at the hilum. Along with pomegranates, the spice known as mace is an aril. Mace is a striking red aril that surrounds a nutmeg.
A slightly different version, called an arillode or false aril, emerges from a different location on the seed coat. Lychee, for example, grows partly from the hilum and partly from the integument or coating of the seed. The same is true for soapnuts. And yew creates a cup-shaped aril fruit, rather than a traditional cone.
Like other fruits, the aril serves as an attractant to herbivores. As birds, animals, and people eat these fruits, the seeds are spread farther and wides, improving the odds of continuing that particular line of genetic information.
Now you know.
As you prepare for a change of seasons, it is common to want to clean things up, to make the garden look a little more tidy, and to create less work for yourself in the future.
Very often, landscape fabric is part of those plans for an easier, weed-free future. Landscape fabric is easy to use and it works. For a while. And at a price that might surprise you.
How landscape fabric is used
Landscape fabric is a semi-porous material that is used to create a weed-free area in a landscape. Advertisements claim that water, air, and fertilizer can still reach the soil while preventing weeds from taking hold. Photos make the end result look lovely and trouble-free. To use landscape fabric, the following steps are used:
It’s that simple. Unless there is a slope. Or if you care about pollution. Or if soil or plant health matter.
Air flow is important
Plant roots and soil dwelling critters need to absorb and release gases to survive. In a healthy environment, oxygen and carbon dioxide move freely between the soil and the atmosphere, allowing for moisture and temperature regulation and other important processes. Without air flow, important soil microorganisms, worms, and plant roots die.
Mulch material matters
Landscape fabric and mulch allow gases to disperse at different rates. Mulching is an excellent way to stabilize soil temperatures, retain moisture, and block weeds, but the material used makes a big difference in gas exchanges. Recent research has shown that, if you cover the soil with landscape fabric, you will slow those gas exchanges by more than 1,000 times than if you had used wood chips. If you were to use plastic sheeting, the gas exchange rates would be slowed by yet another thousand times.
Finally, as plant material, soil, and water collect on top of landscape fabric, weeds will grow anyway. Also, landscape fabric, which is actually plastic, tends to deteriorate over time, being exposed to moisture, microorganisms, and foot traffic. These plastic particles end up in creeks, rivers, lakes, and oceans, as well as in our own air supply. As the mulch shifts, areas are exposed, torn, and the whole thing looks messy as weeds, being weeds, take hold once again.
The next time you see an area covered with landscape fabric, take a closer look at the crowns of nearby trees. Are they dying? Are they putting out suckers? These things are happening because the trees are suffocating.
Instead of using newspaper, cardboard, or landscape fabric to block weeds, simply contact your local arborist and ask for a load of clean wood chips. A nice 4” thick layer of mixed wood chips does an amazing job at blocking weeds and protecting your soil. For free.
Rabbits, hares, and pikas may look adorable, but they can wreak havoc in a garden.
Before we get started learning more about how to protect your plants from these garden mammals, let’s make one thing clear: rabbits are not rodents. Either are hares or pikas.
A different sort of critter
Rats, mice, and voles are rodents. Rabbits, hares, and pikas are lagomorphs. Lagomorphs differ from rodents in two basic ways: teeth and diet. Both rodents and lagomorphs feature incisors that grow continuously. That is why they are always chewing on things. They have to. But rodents have only two incisors, while lagomorphs have four. Also, all lagomorphs are herbivores, while some rodents eat meat. [We learned that one the hard way when I combined our Zebra finches’ habitat with our hamsters’. It was awful.]
Types of lagomorphs
In the world of lagomorphs, there are, you guessed it, rabbits, hares, and pikas. So, what’s the difference?
Unless you live above the tree line, you will probably never see a pika. Pikas are small, sturdy, compact animals that scamper around rocks and boulders as they look for food and avoid predators.
When looking at rabbits and hares, also known as jackrabbits, size matters. Hares have longer legs and ears, and are larger than rabbits. Also, hares change color with the seasons, while rabbits do not. If you were to find a litter of newborns, infant rabbits are blind and hairless, while new hares are born ready to run.
Damage caused by lagomorphs
Being herbivores, rabbits, hares, and pikas will nibble their way through your lettuces, beets, peas, beans, and kale, shear off seedlings with a clean, angled bite, and may even girdle young fruit and nut trees. You can confirm your suspicions by looking around for 1/4" to 1/2” fecal pellets.
Preventing damage by rabbits and hares
Before you put up a fence, you need to know that most advertised ‘rabbit fencing’ is completely ineffective. Rabbits and hares are able to squeeze through incredibly small holes. Use heavy gauge chicken wire instead.
Generally speaking, rabbits will not jump a 2’ fence, while hares may need a 3’ barrier. Since most rabbits and hares can burrow, fencing alone is not enough. Raised beds with an exclusionary hardware cloth base may be your only real solution if these pests insist on eating your garden plants. Young shrubs and trees can be protected with wire or sheet metal wraps. Electric fencing can be used to protect especially valuable plantings.
How to discourage rabbits and hares
You can also reduce the likelihood of rabbits and hares feeling safe enough to feed in your garden by eliminating hiding places. Brush, stone, and wood piles, weedy patches, and hidden corners are all valuable nesting and hiding places for these herbivores. Eliminate enough places to hide and they will be more likely to go elsewhere. Leaving your dogs outside can also discourage unwanted garden feeding.
Commercial repellants can also be used to make plants less desirable to rabbits and hares. I have had some success with Bobbex-R, used against squirrels, but none of these repellants work perfectly. They only last for a while and often need to be reapplied after rain or sprinklers wash it off. Do not use mothballs in the garden, no matter how many people tell you they work. Mothballs are toxic to all of us and have no place in a healthy environment.
Before trapping or discharging these garden visitors, be sure to check your local laws and ordinances. It is not worth a legal battle to protect a row of Romaine.
If you grow raspberries, you should be on the lookout for spur blight. For some reason, blackberries and other bramble fruit are not affected by the Didymella applanata fungi. Red raspberries are more likely to become infected by this fungal disease than other raspberry species, but all raspberries can get spur blight.
Currently found most often in Scotland, Oregon, and Washington, spur blight can significantly reduce your raspberry crop. Knowing what to look for can help you nip this disease in the proverbial bud.
Spur blight symptoms
Spur blight first appears in mid to late summer on new growth, on leaves and around buds. Initial symptoms of spur blight look a lot like anthracnose, fireblight, and cane blight, with brown and purple lesions on leaves, around buds, and on the lower area of stems. These lesions cause buds to shrivel up. By spring, those lesions will look ashy grey and the buds will be weak or dead. Stems that grow from these infected buds will be wilted and weak.
Infected leaflets have triangular-shaped brown areas and they may fall off, leaving the petiole (leaf stem) in place. You might also see dead spots on the canes near petioles. This infection causes premature leaf drop, which weakens the plant overall. As the blight progresses, splits and cracks may form in the bark.
If you look closely, you might see tiny black dots emerging from those cracks. Those dots are fungal fruiting bodies, called pycnidia. If you look at pycnidia with a microscope, they are flask-shaped. Pycnidia formation is followed by a different type of fruiting body, called perithecia. Perithecia are also black, but they are medium-sized and, if you watch, erupting with spores.
Spur blight lifecycle
Spur blight is spread by spores on wind, rain, and irrigation water. These spores are released each time wet weather occurs, even if that wet weather is your garden hose. If that infected water falls on or near young canes, newly forming buds, leaves, wounds, or stoma, infection can occur. Once inside, this disease spreads throughout the plant, overwintering in the lesions.
How to manage spur blight
Proper sanitation and pruning methods will go a long way toward preventing spur blight on your beloved raspberries. In late winter or early spring, before new canes emerge, remove all dead, diseased, or weak canes and put them in the trash, rather than the compost pile. Be sure to keep canes properly spaced for good air flow, and train them up trellising that allows canes to dry quickly and to make it easier for you to water your raspberry plants at ground level. You should also keep weeds away, as they complete for water and nutrients and reduce air flow around the canes. Unless a soil test has indicated a genuine need for fertilizer, avoid feeding your raspberries. The presence of too many nutrients causes plants to produce an abundance of vulnerable tissue.
As always, only buy certified, disease-free plants and place new plants in quarantine. In the case if severe infection, fixed copper or lime sulfur treatments may reduce lesion size and control internal infection if applied when new shoots are 8-10” long.
Believe me when I tell you that it is far easier to prevent spur blight than to treat it. And raspberries are worth the effort.
Strawberry vein banding is a viral disease spread by strawberry aphids, but you will never know it has infected your plants until another virus comes along.
As soon as another virus infects your plants, usually strawberry crinkle, suddenly the leaf veins of your strawberry plants start to turn yellow. And if the strawberry mottle virus comes along, well, those yellowing veins won’t be visible. This mess is called strawberry decline, a topic for another day.
Symptoms of strawberry vein banding
Leaves of infected plants tend to be significantly smaller than the leaves of healthy plants. The yellowing of veins, when visible, first appear in new growth. This yellowing appears erratically; sometimes only part of a vein has turned yellow. The two halves of each leaf may be held closer together than is normal and the margins, or leaf edges, are wavier than normal. Some crinkling of the leaf surface may also occur. As the leaf opens, the bands of yellow become somewhat more obvious.
Symptoms appear more strongly in the second and third leaves, but are not likely in later growth. [Weird, right?] Unfortunately, the other symptoms include stunting and reduced fruit and runner production. Your strawberry crop can be reduced by nearly 20% because of vein banding. As soon as another virus takes hold, you can lose your crop entirely.
Strawberry vein banding vectors
Strawberry vein banding is generally carried by strawberry aphids. It can also be transmitted by taking grafts from infected plants. Strangely enough, coming into contact with dodder can also spread the disease, but sap from an infected plant cannot. Stranger still, a clone of the vein banding virus can infect turnips, a completely unrelated species.
Strawberry vein banding control
In a word, you can’t. Strawberry vein banding can be prevented by only installing certified disease-free plants, placing those plants in quarantine when they first arrive, and removing any plants that you suspect are infected.
Since aphids can fly at certain points in their development, the threat of this and other viruses is constant. All you can do, besides the preventive measures listed above, is monitor your plants for signs of aphids and control them as well as you can. Insecticides and insecticidal soaps work against aphids, but your strawberry plants need honey bees and other pollinators to produce fruit. Those insecticidal controls will impact your helpers, too, so they should be avoided while plants are flowering.
Closely monitoring your strawberry plants and keeping other plants that might host aphids at a distance can go a long way toward preventing vein banding in your strawberry plants.
Strawberry pallidosis is one of several viruses that make up a condition called virus decline.
Infected with only one of these diseases, strawberry plants often remain symptomless. It isn’t until a second virus enters the game that symptoms begin to appear. These other viral diseases include strawberry vein banding, crinkle, mottle, mild yellow edge, and beet pseudo yellows.
Symptoms of strawberry pallidosis
Similar to other strawberry viral diseases, symptoms of strawberry pallidosis include stunting, significantly reduced fruit and runner production, and older leaves turning red or purple. An additional symptom of strawberry pallidosis is that roots are brittle and show fewer rootlets.
Managing strawberry pallidosis
Unlike many other strawberry viral diseases, pallidosis is spread by whiteflies. This makes controlling the disease more difficult. Management strategies are the same for all strawberry viral diseases: only install certified disease-free plants, quarantine new plants, remove infected plants, and control whiteflies as much as you can.
Strawberry mottle is an unassuming viral disease that can cut your strawberry crop by 30%.
Strawberry mottle is one of several viruses that can affect strawberries. Appearing on its own, the damage tends to be relatively isolated. All too often, however, more than one virus appears at the same time. Collectively, this condition is called virus decline and it can eliminate any chance at enjoying a sweet, juicy strawberry from your garden, no matter how well you care for your plants.
Vectors of strawberry mottle disease
Strawberry mottle is carried by insects, most commonly by strawberry, melon, and cotton aphids. This virus is also spread by vegetative propagation of infected plants. Unlike the strawberry mild yellow edge virus, which is retained in an aphid’s gut for its lifetime, the strawberry mottle virus can only be transmitted for 2 or 3 hours after an aphid or other insect has fed on an infected plant. This makes outbreaks remain relatively localized. [Ten feet away probably looks impossible to a flightless bug that is only 1/8” long.]
Symptoms of strawberry mottle
As insects pierce plant cells to suck out the sugary sap, viruses move from the insect’s saliva to the plant. As viruses tend to do, these pseudo-lifeforms start reprogramming a plant’s cells to produce more viruses, which then clog the works.
Strawberry mottle first appears on young leaves as smaller than normal leaves that may also show yellow distorted areas. Plants may be stunted and they certainly produce less fruit and runners than they might otherwise. As the disease progresses, symptoms become more severe, with older leaves turning red.
Strawberry mottle management
Strawberry mottle is more likely when plants are left in place over the winter, but that doesn’t mean you have to rip out your plants every year. [Note: don’t actually rip plants out of the ground. Instead, cut them off at soil level to leave valuable soil microbes in place.]
As always, to reduce the likelihood of strawberry mottle appearing in your garden, only buy certified disease-free plants and always place new plants in quarantine. As much as possible, try to control aphids around strawberry plants. If a plant becomes infected, remove it.
For some reason, strawberry plants tend to get infected with more than one virus at the same time. Strawberry mild yellow edge virus is one of those diseases
Strawberry mild yellow edge virus is a long name for a disease that can reduce your strawberry crop by as much as 30%. Strawberry mild yellow edge virus often appears at the same time as the mottle virus, both of which are transmitted by some aphid species. Nematodes may also add raspberry ringspot virus to the mix.
Strawberry mild yellow edge virus symptoms
As with most viral diseases, stunting is a common symptom of strawberry mild yellow edge virus. Older leaves may turn bright red, but leaves around the crown nearly always exhibit yellow margins or edges, hence the name. These yellowed areas eventually die and turn brown. Leaf cupping may also occur.
Since these symptoms look a lot like water-stress, fertilizer burn, overly acidic pH, boron toxicity, or bad weather, it is important to rule those things out before deciding on a plan. Once strawberry mild yellow edge virus has made an appearance in your garden, there are steps you can take to minimize the damage.
How to manage strawberry mild yellow edge virus
Even though the fruits of infected plants are still edible, plants infected with strawberry mild yellow edge virus should be removed to reduce the chance of spread. Aphids carrying the strawberry mild yellow edge virus are disease vectors for life. The only thing to do if the disease is present is to use insecticidal soap on each and every aphid that might be a carrier. Just be sure to do this at a time when honey bees and other pollinators will not be attending the flowers. Common lambsquarters and other Chenopods can also carry this disease, so keep these plants away from your strawberry plants.
This disease is most common when plants are grown using a matted-row method. The matted-row system allows parent plants to send out runners, or daughter plants, which will produce fruit the following spring. This is a very productive method that has been around for a long time. It gets its name because the runners end up intertwined, creating a mat. The only problem with the matted-row system is that it means plants are in place for a longer period of time. This makes infection more likely.
As always, place new plants into quarantine until you are sure that they are disease-free.
Strawberry crinkle might sound like a delicious new candy bar, but it is one of the most destructive viral diseases a strawberry plant can face.
Strawberry crinkle virus was first seen in Oregon and California in 1932 and is now found worldwide. Spread by aphids, this disease is commonly seen in tandem with other aphid-transmitted diseases, such as mottle, mild yellow edge, pallidosis, and strawberry vein banding. As aphids feed, their saliva transfers the virus to every plant they visit.
Strawberry crinkle virus symptoms
Wilting, reduced runner production, smaller fruit, deformed and/or streaked flower petals, and crinkled leaves are all symptoms of strawberry crinkle virus. Vein spotting may also be seen, as well as lesions on petioles (leaf stems) and stolons. Infected plants may appear top-heavy, exhibiting a form of epinasty. These symptoms can vary in intensity.
Strawberry crinkle virus management
Since bees are so important to strawberry formation, insecticides are generally not an option against the aphids that carry this disease. Use these tips to prevent strawberry crinkle virus from impacting your strawberry crop:
Hopefully, your strawberry plants will never become infected with the crinkle virus. Until we figure out a sustainable way to get rid of aphids, well, be on the lookout.
Root hairs are where water absorption occurs. Since that water contains nutrients found in the soil, root hairs are important. And fragile.
You might expect root hairs to grow along the entire length of a root system, but that’s not what happens. Root hairs only occur in specific areas, or zones, of a root system.
Roots start out as undifferentiated cells. The very tip of a root is called the root cap, which protects the growing root as it moves through the soil. The next zone is where cell division takes place. As more cells are produced, the root cap is pushed forward. This growth is a relatively continuous process throughout the life of a plant. As new cells are produced and the root moves forward, the older cells stretch and create storage pockets called vacuoles. This is called the zone of elongation. Finally, growth and elongation are complete and root hairs can begin to emerge. This is called the zone of maturation.
The reason root hairs do not appear right away in the growth process is because they are so delicate that they would be sheared off as the root moves through the soil. This is also what causes transplant shock. The act of transplanting can shear off a majority of the root hairs as the soil gets jostled about and uninformed gardeners tamp down the soil. Rather than crushing delicate root hairs, mudding in new transplants protects those important root hairs.
Did you know that the reason root hairs are so evenly spaced along a root is because each hair secretes a poison that prevents nearby cells from producing their root hair? I didn’t either.
How root hairs absorb water and nutrients
Nutrient-rich water is pulled into the cytoplasm of root hair cells by osmosis. Root hairs also secrete malic acid, which helps convert minerals into ionic forms that are easier to absorb. Organic molecules in the soil, called chelates, also help root hairs absorb nutrients.
Root hairs as defense mechanism
Because root hairs are so small, they make it very difficult for harmful bacteria to enter the plant through the xylem. When beneficial bacteria, such as those which help legumes fix atmospheric nitrogen, appear, root hairs curl around the welcome visitor. This allows an infection thread to connect the two for everyone’s benefit. Helpful soil microorganisms, called mycorrhizae, are small enough to enter a plant’s root system through the root hairs. Root maggot larvae feed on root hairs.
Plants use phosphorus to grow healthy roots. Before you add more phosphorus to your soil, be sure to send out a sample for a soil test. Too much phosphorus can be just as bad, or worse, than not enough.
Avocado lace bugs, also known as camphor lace bugs, can cause problems on avocado, red bay, and camphor trees, along with azaleas and rhododendrons.
Native to Florida, Texas, the Caribbean, French Guyana in South America, and eastern coastal Mexico, avocado lace bugs (Pseudacysta perseae) are not a serious problem when found in small numbers. Or where they have no natural predators.
Avocado lace bug description
Avocado lace bugs get their name because of the lacy venation of their wings, but the way they protect themselves with a lacy cover as they hide on the underside of leaves but be another good reason. That cover is actually the avocado lace bug’s thorax and forewings.
Avocado lace bugs are only 1/16” to 1/12” long, brown, orangish, or black and oval-shaped. They tend to cluster together, creating what looks more like a messy fungal growth than an insect colony. If you look closely, with a hand lens, you would see that avocado lace bugs have a black or brown head or thorax, with white, orange, or brown legs, wing covers, antennae, and abdomen.
Avocado lace bug nymphs are dark and spiky, with pale legs and antennae. Eggs look like sprinkled black pepper even though they are actually oblong and yellow. The black color comes from the fact that these tiny oblong eggs are smeared with what looks like poop.
Avocado lace bug lifecycle
Yes. That’s what I said. Poop. Female avocado lace bugs lay their eggs and then smear the area with a sticky, tar-like substance that looks like poop. Under that protective layer, nymphs molt 5 times as they grow before emerging as adults. Avocado lace bugs have several generations each year and all developmental stages can be present at any one time.
Avocado lace bug damage
Avocado lace bugs are sap suckers. As such, they pierce the underside of leaves and siphon away nutrient rich fluids. This feeding, while trivial in small numbers, can cause stippling. As feeding progresses, other symptoms appear, such as leaf tip burn that looks like salt damage, leaf discoloration, and early leaf drop. Large infestations can result in defoliation, sunburn damage, and reduced fruit production.
As in any case where plant cells are pierced, this feeding also provides points of entry for fungal diseases, such as anthracnose.
Avocado lace bug control
Natural predators should keep avocado lace bug populations in check. These beneficial insects include jumping spiders, lacewing larvae, lady beetles, and predatory mites and thrips, as well as parasitic wasps.
If avocado lace bug populations reach troublesome numbers, keep your trees healthy with a thick layer of mulch, good drainage, and regular irrigation. Insecticidal soaps are somewhat helpful against avocado lace bugs.
Be on the lookout for this pest. If you suspect your tree is hosting avocado lace bugs, contact your local County Extension Office right away. As always, place new plants and bare root trees in quarantine before adding them to your garden.
Like other stink bugs, Uhler’s stink bug has a shield-shaped body. Native to North and Central America, Uhler’s stink bugs will damage nectarines, pistachios, and tomatoes, along with seeds, grain, other fruits and vegetables, ornamental plants, legumes, and tree leaves.
Uhler’s stink bug identification
Uhler’s stink bug (Chlorochroa uhleri) looks a lot like green stink bugs (Acrosternum hilare), which may have a a red, orange, or yellow outer edge, and Say stink bugs (Chlorochroa sayi), which are green with a white border. Uhler's stink bugs tend to be slightly larger than other stink bug species. Uhler’s stink bugs may also turn a dustier green that almost looks tan and the outer band may pale to the point of looking nearly white. Quite honestly, unless you are looking at a beneficial rough stink bug (Brochymena sulcata), you are looking at a pest that should be hand-picked and destroyed.
Damage caused by Uhler’s stink bugs
Uhler’s stink bugs eat fruit by piercing the surface and sucking out the sugary sweet juice. At first, those feeding spots may look like tiny, translucent blue-green dimples. If you cut into the fruit, you will see the fruit has turned into grayish white pithy tissue that doesn’t look the least bit appetizing. These pests can also transmit tomato bacterial spot and create points of entry for other pests and diseases.
Uhler’s stink bug controls
Insecticides are ineffective against stink bugs, but that may be a good thing. Instead of spraying chemicals that kill off beneficial insects, a healthy, biodiverse garden will likely be home to assassin bugs, parasitic wasps and flies, such as the tachinid fly (Trichopoda pennipes) and the Trissolcus basalis wasp, which will parasitize stink bug eggs. Birds, spiders, toads, and other insect eating critters will also help keep stink bug populations down.
Your best stink bug management program simply involves walking around and looking for them, hand-picking them and depositing them in a container of soapy water or feeding them to your chickens. You may have to be quick, as stink bugs tend to scramble to the opposite side of a twig or branch if they sense someone is looking for them. You will need to monitor for stink bugs from the time buds emerge until the end of the harvest season.
These pests are often found overwintering in common mullein, curly dock, and Russian thistle. If stink bugs have been a serious pest in the past, pull mulch away from fruit trees before green fruit appear. After the harvest, simply push the mulch back into place.
The red noodle bean plant looks spectacular, grows rapidly, and provides a bountiful harvest.
A dear friend gifted me with a packet of red noodle bean seeds a while back. As they were a type of pole bean, I planted the seeds around things they could climb and watered them regularly. At first, nothing seemed to happen, as is normal in the world of gardening. Then I went away for a few weeks. When I returned, I was delighted to find my red noodle beans had completely lived up to their reputation. [Thank you, Carol!]
The red noodle bean story
Red noodle beans originated in Africa but are more commonly considered to be from China. Rather than being related to the common bean (Phaseolus vulgaris), such as kidney beans, pinto beans, and black beans, red noodle beans are more closely related to cowpeas and yard long beans (Vigna unguiculata).
Red noodle bean description
These climbing beans start out looking much like other pole beans. Heart-shaped leaflets appear in groups of three as tendrils take hold wherever they can, pulling the vine upward. Lovely small white, pink, or lavender flowers appear along the way, but are easily overlooked. The real surprise comes when the pods appear. Pairs of striking scarlet pods can reach over a foot-and-a-half in length.
How to grow red noodle beans
Red noodle bean seeds should be planted 3/4-1” deep and 4” apart. Like other legumes, red noodle beans have delicate root systems that do not recover well from transplanting. These plants need heat to grow, so be sure to install them in a sunny location after the soil has warmed from its winter nap. In fact, where other legumes succumb to scorching summers and drought, red noodle beans thrive.
Vines need a sturdy support as they can reach 8’ in length or more. Trellises, cattle panels, fences, tuteurs, old ladders and pergolas can all be used as supports. Plants will need a thorough watering every 7-10 days to develop deep roots. Because red noodle beans are legumes, they do not need nitrogen fertilizer. In fact, they generally don’t need fertilizer at all, assuming your soil is healthy. You will need a soil test to know if that is the case in your garden.
Being native to tropical rainy areas, red noodle beans need a fair bit of irrigation, just be sure to allow the soil to dry out between waterings to avoid many of the diseases common to legumes.
Red noodle bean pests and diseases
Red noodle bean pests include birds, gophers, rabbits, rats and squirrels, along with ants, mites, and aphids. Those aphids may also bring mosaic viruses to your red noodle bean crop, so monitor closely for those insidious pests.
Harvesting red noodle beans
Plants start producing pods within 80 days. By harvesting pods as they appear, you will stimulate the vines to continue producing. In other words, the more you take, the more they make.
Pods can be harvested when pencil thin to be used whole in stir-fry, or you can allow them to reach full size to harvest what will dry into small, red beans. Keep in mind that allowing the beans to dry on the vine will slow or halt pod production. When harvesting, be sure to leave the buds above the pods in place. These buds can produce multiple sets of pods over time.
You can also succession plant red noodle beans to make full use of your local growing season.
Give red noodle beans a try! You are going to love how they look (and taste)!
Black beans are sweet, meaty beans that are native to the Americas and often used in South American, Cajun, and Creole recipes. Black beans are delicious, easy to grow, and dried beans can be stored for 2 years before they start losing their flavor.
Black bean plants
Black beans (Phaseolus vulgaris) are legumes. This means they have nodules on and in their roots that allow them to fix atmospheric nitrogen into a form that they and neighboring plants can use. This nitrogen is only available until legumes begin flowering and producing pods. At that point, they keep the nitrogen for themselves.
The large, familiar seeds of black beans split in half, which tells us that they are eudicots. This means that the vascular bundle forms a ring within the stem, plants have a taproot, and flowers generally have petals that appear in multiples of four or five.
Black beans get their black color from flavonoids called anthocyanins. These are the same water-soluble pigments that give purple cauliflower and blueberries their color.
Black bean varieties
Black beans come in both bush and pole varieties. Pole varieties will climb trellises, cattle panels, and other vertical surfaces, and they tend to be indeterminate, which means they will continue producing pods. Bush varieties tend to be determinate and will produce all of their pods within a two-week time frame. Pole beans produce more pods than bush beans, but bush varieties are best if you are planning on doing any canning.
Whichever variety you should, beans should be harvested as soon as they have plumped up. Leaving them on the plant for too long makes them tough.
How to grow black beans
Beans are generally planted directly in the soil in spring and early summer. If planted too soon or too late in the season, the seeds will simply rot in the ground. You can start black bean seeds in smaller pots, but they have delicate roots and do not transplant well. You can also grow them in containers. Just keep in mind that bean root systems need 16-24” deep pots to thrive.
NOTE: As tempting as it may be to use an inexpensive bag of dried black beans from your local grocery store as your seeds, don't do it. Grocery store items are safe to eat. That does not means that they are safe to grow. Many grocery store plants can carry pests and diseases that may take years to be rid of. Instead, invest in certified disease-free seeds and transplants. Your garden is worth it.
Black beans prefer warm temperatures (above 70°F) and need at least 6 hours of sunlight each day. They prefer loose soil with a pH of 6.0-7.0. Because they can fix atmospheric nitrogen, there is no need to feed bean plants with nitrogen. If a soil test indicates a nutrient deficiency, you can top dress around plants for the best yield.
Seeds should be planted 1-2” deep and 6-8” apart. Water enough to keep the soil moist (but not soggy) until germination occurs. This should take 8-14 days. After that, water deeply every few days, allowing the soil to dry out between waterings. For a continuous harvest of black beans, you can start new seeds every week or two throughout the growing season. This is called succession planting.
Hand-weed around bean plants by cutting weeds off at soil level. This avoids disturbing bean roots while eliminating competition for water, nutrients, and sunlight. This practice also leaves valuable soil microorganisms in place, where they can benefit the bean plants.
Black beans take 80-140 days to mature, depending on environmental conditions and variety.
Black bean pests and diseases
Disease that tend to affect beans include bean rust, curly top, damping off, Fusarium root rot, mosaic viruses, powdery mildew, and white mold. Most of these diseases can be prevented by avoiding overhead watering and allowing the soil to dry out between waterings.
The real battle, when growing any type of bean, is the army of pests that may go after your crop. These pests include aphids, armyworms, bean weevils, corn earworms, cucumber beetles, cutworms, darkling beetles, earwigs, grasshoppers, leafhoppers, leaf miners, loopers, Lycaenid pod borers, Lygus bugs, nematodes, salt marsh caterpillars, seed corn maggots, slugs and snails, spider mites, stink bugs, thrips, whiteflies, and wireworms, but don’t let that stop you from trying your hand at these productive, delicious, easy to store beans. Three-year crop rotations can help prevent or break the disease triangle for many of these problems.
Beans are easy to work with, they improve your soil, and are a satisfying crop to harvest.
Cherry, apple, peach and plum trees are all susceptible to a fungal disease called Cytospora canker.
Cytospora canker is a collection of symptoms caused by several species of Cytospora fungi. This disease is also seen in ash, birch, cottonwood, elm, maple, willow, spruce and other conifers. Some Cytospora fungi are host-specific, while others can infect several different tree species. Sadly, Cytospora canker can be fatal.
Cytospora canker lifecycle
Cytospora canker fungi infect trees and shrubs that are stressed or weakened by injury, frost damage, drought, or pests. Spores are carried by wind and rain. Infection can occur at any time of year, but is more likely during dormant periods, when trees are less able to defend themselves. Fungal spores enter through tiny wounds in the roots or bark and begin growing in the xylem and phloem. Eventually, the branch is girdled, blocking the flow of water and nutrients, and the branch dies. If infection occurs in the trunk of the tree, the tree will die.
Cytospora canker symptoms
The first sign of Cytospora canker is often the random die off or flagging of tree or shrub branches. Closer inspection reveals cankers on stems and branches. These cankers tend to be long and narrow and may or may not be sunken or discolored. These fungi grow so rapidly that discoloration and sunken areas do not always have time to form, but the bark may split along the edge of the cankers as the tree tries to defend itself. These cracks allow for the formation of a callus that blocks the fungi from entering. Sometimes this works, and sometimes it doesn’t. In some cases, girdling occurs without any visible cankers. Gumming may also occur. Gumming is when stems and fruit ooze out a sticky sap. This is another form of tree defense.
If you cut into a diseased stem, you may notice discoloration and a funky smell. If you see tiny black spots, you are looking at fruiting bodies of the fungi.
Cytospora canker prevention and control
The easiest way to prevent Cytospora canker is to keep your trees and shrubs healthy in the first place. Healthy plants are less likely to become stressed enough to be vulnerable to infection by fungal spores in the first place.
Since drought and flooding are the most common conditions that make trees susceptible to Cytospora canker, regular irrigation during summer and proper drainage in wetter months can prevent infection. These other tips can help prevent Cytospora canker:
Once infection occurs, remove any affected stems and branches by cutting close to, but not damaging, the branch collar. Be sure to disinfect your cutting tools with bathroom cleaner or ethyl alcohol between each cut. Then apply a fungicide to each cut. Do not use any other wound dressing, as these treatments can trap spores and moisture where you least want them.
There are no known chemical controls for Cytospora canker, so keeping those trees and shrubs healthy is your best bet.
Common lambsquarters (Chenopodium album) may be edible, but you probably don’t want it anywhere near your garden.
California goosefoot (Blitum californicum) is also known as lambsquarters, but is a close cousin to spinach and the subject of another post, another day.
Lambsquarters grows pretty much everywhere without any help from any of us. Sadly, this tenacious weed also plays host to several diseases.
Diseases of lambsquarters
These weeds are susceptible to a large number of plant diseases. The list of diseases commonly found on lambsquarter, and the crops they infect, include:
The green peach aphid, a serious disease-carrier, seems to prefer lambsquarters, which gives us yet another reason for pulling these weeds out as soon as they are seen.
Lambsquarters start out with tiny dull bluish oblong leaves. You may see a reddish purple on the underside. As leaves mature, they take on more of a toothed, lance shape. Leaves are covered with a white, powdery coating, especially when new. Stems are sometimes tinged red or purple. Flower clusters form much like the seed heads of millet and quinoa.
Pull them out. Dig them out. Don’t let them go to seed.
While it is okra pods that we normally think of eating, okra leaves and flowers are also edible. Cousin to hollyhocks, cocoa, cotton, hibiscus, and mallow, okra is a simple addition to your garden.
Okra (Abelmoschus esculentus) is an attractive plant. Large flowers tend to be white or yellow with red or purple spots at the base. These are big, impressive plants, similar to artichokes. They can reach 5’ in height and 2 or 3 feet wide.
How to grow okra
Okra prefers hot, sunny weather and warm soil (at least 75°F). It will tolerate clay soil but grows best in soil with lots of organic material. Okra can be planted in large containers.
The roots of okra seedlings are very delicate and easy to damage. Seedlings can be difficult to find, depending on where you live. Okra can be started from seeds, but it is a slow growing plant. Seeds should be sowed 3/4” deep in mounds.
Okra is a heavy feeder, so top dressing with some aged compost when plants are 8” tall and again when pods set and when plants are 4’ tall. This will ensure they have all the nutrients they need. [Of course, it is always a good idea to get a soil test, so you know what your plants are growing in.] Over-fertilization of okra creates huge, beautiful leaves and zero pods.
Once pod-formation begins, be sure to harvest pods every other day, while they are less that 4” long. Larger pods are tough and inedible. If pods are allowed to ripen on the plant, pod production will stop.
Okra pests and diseases
Okra is frequently attacked by aphids, cutworms, earwigs, flea beetles, and whiteflies. You can protect young okra plants from earwigs and cutworms by using brassica collars.
Being susceptible to Fusarium wilt and Verticillium wilt, okra should not be planted where tomatoes or peppers have been grown recently.
Okra is a drought-tolerant plant, but it grows best with regular irrigation. Some people are sensitive to okra leaves, so you might want to wear gloves. Just in case.
Nurse cropping is a form of companion planting in that specific plants are installed to provide one type of protection or another for young crops as they become established.
Nurse crops protect young perennials
In commercial agriculture, nurse crops are fast-growing annuals that are planted along with perennials, such as alfalfa, to help those perennials become established. This gives the long term crop protection from pests as it is getting started.
Nurse crops as trap crops
Trap crops are installed around or near desirable crops because of the way they attract or repel specific pests. In some cases, trap crops interfere with a pest’s lifecycle or kill it outright. In other cases, the trap crop is “harvested” after pests have appeared to remove them from the garden.
Nurse crops are frequently used as traps crops. For example, wireworms are a big problem for strawberries. In one study, strawberries planted alone had a 43% mortality rate, while strawberries planted two weeks before wheat was added had a 27% mortality rate. When wheat was planted 8 days before the strawberries, that mortality rate dropped to 5%. That’s a significant savings in strawberry starts, just by broadcasting a handful of wheat berries a week ahead of time!
Pros and cons of nurse cropping
Like every other plan of action, nurse cropping has pros and cons. The benefits of nurse cropping include reduced weeds, wind and erosion. Also, perennial seedlings are protected from excessive sun in their first weeks of growth. Oats and other cereals are common nurse crops. As such, another benefit is that the nurse crop can be a harvestable edible in its own right.
The potential problems associated with nurse cropping is that the nurse crop does use up water and nutrients. It may also become a type of weed itself.
You can use nurse cropping in your garden by starting cereal grains in a bed a week or so before planting something else. If you don’t harvest it, the local birds and other wildlife will appreciate the buffet and more tender plants will benefit, as well.
You can grow a surprising amount of food in your own yard. Ask me how!