Potato virus Y (PVY) is the Big Daddy of potato problems, right up there with early blight. And potatoes aren’t the only plants at risk. Peppers, tomatoes, and groundcherries can all catch PVY. Losses can be as high as 80%. Infected potatoes that make it to harvest don’t last in storage. And who wants to eat an infected potato?
Potato virus Y is spread by aphids, but not in their saliva. Instead, these microscopic potyviruses stick to aphids’ mouthparts (stylets). As the vector aphids feed, they spread the disease. Your shoes, clothes, and garden tools can also transfer this virus.
The many flavors of PVY
PVY used to be easy to identify. This meant infected plants were removed right away, and the spread of disease was limited. Like another virus that shall remain unnamed, the PVY virus has been mutating a lot lately, making it more difficult to manage. Recent mutations have fewer symptoms, making infected plants harder to identify. They stay in place longer, increasing the spread of disease to nearby plants.
The most common variations of PVY include PVYO (ordinary), PVYC (uncommon), PVYN (necrotic), PVYNTN (tuber necrosis), and PVYN-Wi (a recombinant strain). The tuber necrosis strain can cause potato tuber necrotic ringspot disease (PTNRD). Botanists sure do like their acronyms, don’t they?
Potato virus Y symptoms
Brown spots on leaves and tubers are the first sign of potato virus Y infection. Other symptoms vary depending on the plant age and health at the time of infection, environmental conditions, potato cultivar, soil health, virus strain, and the presence of other viral diseases, such as PVA, PVS, and PVX. Chlorosis, curved midribs, leaf crinkling, mosaic, mottling, and vein distortions are early signs of PVY. Infected leaves feel rough (rugose) compared to healthy leaves. If you look on the underside of infected leaves, you will see dark lesions and black streaks on the midrib. As the disease progresses, leaf loss and stunting are common. This disease is easily mistaken for calico (alfalfa mosaic virus).
Potato virus Y management
Chemical treatments are not effective against potato virus Y, so these good cultural practices are your best line of defense:
Potatoes come many of colors: blue, purple, red, yellow, and white. But why does potato skin turn green sometimes, and can it hurt you?
The simple answer is yes. Green-skinned potatoes can make you sick. According to WebMD, you can peel green-skinned potatoes, but those potatoes are still not entirely safe to eat. It’s all about toxins.
Like other members of the nightshade family, potatoes produce toxins. The toxins produced by potatoes are called solanine and chaconine. These toxins are part of a potato plant’s defense mechanisms. They are produced in abundance when tubers are exposed to light. The green color under a potato’s skin is chlorophyll. You can use it as a signal that lets you know a spud’s chemistry has changed.
Why do potato skins turn green?
Tubers belong underground. Uninjured potatoes are relatively stable in cool, dark locations. Expose them to light once and nothing happens. Expose them to light several times and things start happening. Imagine, if you will: First, they get dug up at the farm and see daylight for the first time. They get moved to a shipping truck and roll down the freeway with more sunlight. Drop them off at the processing plant and they get more light. You get the idea. By the time they leave the grocery store (where they got even more light) and arrive at your kitchen, some of those potatoes will have shifted from storage mode to growth mode. That’s when trouble starts.
Is peeling enough?
Many people say that peeling the green skin away makes the spud safe to eat. That’s not entirely accurate. While most of those toxins are stored in the skin, they are still present in the rest of the potato. Just as a moldy cheese will also have mold growing throughout its interior, even if you can't see it. Peeling a green-skinned potato may not be enough. And cooking them does not affect the toxins.
All that being said, if you are generally healthy with a good digestive system, you may be fine with an occasional green-skinned potato. If you notice any of these symptoms, however, see a doctor:
Preventing green-skinned potatoes
You can’t control what happens to your potatoes before they arrive at your home (assuming you haven’t started growing your own yet). What you can do is store your potatoes in a dry, cool location with as much darkness as possible. Your refrigerator or pantry are ideal.
If an occasional green-skinned potato appears, throw it in the trash if it was from the store. If it was homegrown, you can.add it to the compost pile or plant it instead of putting your tummy at risk.
Powdery scab may sound like an adolescent skin problem, but it is a disease of potatoes that leaves them looking, well, scabby. You can cut away the affected bits and eat the rest of your potato, but the skin is where most of a spud’s nutrients are stored, so that’s a shame.
Also known as corky scab, let’s see what we can learn about this disease and how to prevent it.
The powdery scab disease
Powdery scab is caused by one-celled creatures known as Cercozoa. They are not bacteria, fungi, or viruses. Instead, they are parasitic amoebas. Specifically, it is Spongospora subterranea that causes powdery scab. These microscopic critters exist around the world. Tomatoes, nasturtiums, and other members of the nightshade family can also become infected with powdery scab. Once infected, plants are more susceptible to other diseases, such as potato mop-top and potato scab. Powdery scab spores can remain viable in the soil for up to 10 years.
Powdery scab symptoms
Small, purple lesions that look like pimples first form on a potato’s skin. Those lesions grow bigger and bigger and then they rupture, sending spores in all directions. Those spores are white. To the naked eye, these spore clusters look like scabs. You may also see galls on infected roots, leaf wilting, or discolored stems.
How to prevent powdery scab
The easiest way to prevent powdery scab in your potato patch is by planting only certified disease-free eye potatoes. I know it’s tempting to use spuds and other vegetable starts from the grocery store. They’re certainly convenient, and you already have them, but they can bring a world of hurt to your garden. Produce bought at grocery stores is certified safe to eat, but it can still carry soil-borne diseases that may linger in your soil for many years. If you are growing in containers, this is less of a problem. If a disease appears in that case, you can toss the soil in the trash and start over. Hopefully, you catch it before spores have been released. Other practices that will help prevent powdery scab include:
Infected potatoes aren’t the only way powdery scab can enter your garden. To prevent this disease, you need to monitor these other potential pathways:
I’m a big proponent of buying used garden gear from yard sales and thrift stores, but you have to wash everything thoroughly before using it. And always put new plants into quarantine.
Chemical controls are not effective against powdery scab.
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!
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?
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?]
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.
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.
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.
Did you know that paprika peppers contain more Vitamin C than lemon juice and that their flavor improves when heated?
Now you know.
In light of the 2016 $1 million potato photo sale, I thought I would share the amazing story of potatoes.
Food storage and geophytes
Potatoes are tubers. Tubers are are type of geophyte. Geophytes are plant organs used to store food and water. They are also used in asexual reproduction. There are several types of geophytes: bulbs, corms, and everything else. That “everything else” is what we call tubers. Potatoes and yams are stem tubers. Stem tubers can emerge from modified stems. These stems can start out as stolons or rhizomes. Stolons are stems that grow at or just below the soil surface as “runners”. These “stems” are converted into adventitious roots at the nodes and what would have been a bud above ground becomes a spud below. Rhizomes are 'runners' that connect a parent plant to its offspring.
A modified stem
The “eyes” seen on a potato are actually stem nodes. Within each potato, you will find the same plant cells you would find above ground: vascular bundles, pith (spongy tissue), and cortex (outer tissue). Now here’s the funny part. While our standard spud grows from stem tubers, sweet potatoes grow from root tubers. The internal cell structure is very different. Root tubers have no nodes. That is why sweet potatoes have a more elongated form. At one end, you will find crown meristem tissue, which grows into stems and leaves. At the other end, called the distal end, the tuber produces roots. But enough of that, let's start growing some potatoes!
Commercial potato farming
Growing potatoes is surprisingly easy and I urge you to give it a try. In his book, The Botany of Desire, Michael Pollan describes how one potato farmer would not feed what they had grown commercially to their family, due to all the fungicides, herbicides and pesticides that are applied to commercial crops. That was a little misleading, since those chemicals are heavily regulated and rarely last long enough to be found on the food we eat. The real reason behind growing an untreated patch of potatoes was so they could enjoy the potatoes whenever they wanted them, rather than having to wait for the chemicals to dissipate. Personally, I don't use chemicals.
How to grow potatoes
While potatoes can can certainly be grown from spuds bought at the grocery store, this is a bad idea. Foods bought in the store are safe for human consumption, but they are not guaranteed to be free from common garden pests and diseases. You are far better off buying certified “seed potatoes”.
The easiest way to grow potatoes is in a barrel, raised bed, or in a tower. If potatoes are planted in the ground, you will be finding rouge spuds for many years. Also, digging them up from the ground is, let’s face it, work. Growing potatoes in containers makes harvesting significantly easier and they make nice summer patio plants!
To begin, fill the bottom of the container(s) with 4" of loose, moistened soil. Cut seed potatoes into 2 inch chunks, making sure that each chuck has several eyes (small seed potatoes can be planted whole). Place the chunks 6" apart and cover them with 3" of moistened soil and repeat the process until the container is filled. Water lightly and be sure to place planters where they will get lots of sun. To build a tower (which works nicely for strawberries and herbs, too), simply take a section of chicken wire or hardware cloth and create a cylinder. Landscape cloth can also be used, but it may fall over. You can also grow potatoes indoors, near a window, if it gets enough light. Potatoes need loose, well-drained soil and frequent, light watering. Never let potato plants sit in water, they will rot. Potatoes use a lot of nitrogen and potassium, and they prefer acidic soil (as low as 4.8 pH).
At first, it will look as though nothing is happening. As a gardener, you know the value of patience. With time, water and sunlight, tubers will send out roots and stems that will pull nutrients from the soil and create carbohydrates out of sunshine. (Don’t you just love photosynthesis?) Before long, the container will be filled with lush, green growth. Aside from occasional watering and feeding (aged compost works great!), that’s all you have to do until it completes the season’s life cycle.
Eventually, the lush above ground growth will start to die off. When it starts looking ragged, dump the contents of the container out on a tarp and remove the mature potatoes. Now comes the really cool part: mix the remaining soil with some aged compost and do it all again with the immature spuds! I have been growing potatoes from the same batch of seed potatoes since 2011. To me, homegrown potatoes taste far better than store bought spuds.
Pests and diseases of potato
We’ve all heard about the Great Potato Famine. Over one million people died and another two million abandoned Ireland, all because of potato blight. Potato blight causes the tuber to rot in the ground. Other potato diseases include charcoal rot, corky ringspot, cucumber mosaic, curly top, fusarium wilt, leafroll, pink rot, sclerotium stem rot, cankers, verticillium wilt, and white mold. Many of these diseases can be prevented with good drainage and proper spacing between plants.
Common potato pests include aphids, beet leafhoppers, cutworms, flea beetles, potato psyllids, potato tuberworms, silverleaf whiteflies, Colorado potato beetles, Jerusalem crickets, and wireworms. But don’t let these threats stop you from creating your own potato patch.
Start your own potato patch today!
If you like your food spicy, chili peppers are a garden necessity.
Hot pepper plants are small shrubs with striking red, orange, or yellow fruits, depending on the variety. These plants look great in a landscape and they can provide you with peppers all summer long.
How to grow hot peppers
These plants need a long growing season to reach full flavor. Seeds are usually started 6 to 8 weeks before the weather is warm enough for them to be outside. Peppers need nighttime temperatures that are at least 50 to 55°F, to prevent blossom drop. Start with clean, disinfected pots that are 2 to 3 inches deep and that have drainage holes. You can disinfectant old containers by washing with a household cleaner, such as Lysol, and allowing them to air dry in the sun. This is an easy way to prevent future disease and pest problems. In the same vein, use new potting soil, rather than dirt from your garden. Seedlings are much more delicate than your mature plants, which may be strong enough to withstand existing pests or diseases. Also, use seed designated with a letter “V” - this indicates resistance to verticillium wilt.
Fill containers 3/4 full of moist, nutrient rich, organic potting soil. Seeds should be placed 1 inch apart and covered with 1/4-inch of soil or vermiculite. Wet the surface without disturbing or uncovering the seeds. You can use plastic food trays to hold your pots - the clear plastic covers make it easy to maintain moisture levels and the bases protect your furniture. Plastic wrap held in place with a rubber band can also be used. Once seeds germinate, remove the covers. Be sure to label your pots - popsicle sticks work well and they decompose in the garden later on.
Since chili plants are generally started when it is colder than their seeds like, you may want to invest in a seed heating mat. [Put aside the temptation to use that old heating pad - they get too hot, are not designed to handle moisture, and can be a fire hazard.] Sprouted seeds will need full sun or a grow light. Keep the soil moist, but not soggy.
Caring for seedlings
As the first set of true leaves emerge, thin plants to 2 inches apart or up-pot into larger containers. Water every other day, to avoid hydrophobic soil. Pick up your pots to make sure they feel heavy from the water. Check seedlings regularly for signs of aphids, mites, or snails. These pests can be hand-picked or wiped off with a wet paper towel. Continue to up-pot until outdoor temperatures are warm enough for your chili peppers.
Transplanting hot peppers
Prepare your seedlings to be transplanted by watering them to the point of run-off. Then, place one hand over the soil, with the plant stem between your fingers, and flip the pot upside down. You may need to jiggle or tap the pot to break the soil loose. If roots have really taken hold of the pot, use a sharp, clean knife to cut along the sides of the pot. Seedlings should be planted in a sunny location, 10 to 18 inches apart, depending on the variety. If watered regularly, chili peppers perform especially well in heat islands.
You can improve the plant’s root system by removing any growth from the bottom 1/3 of the stem and burying those nodes below the soil surface, the same way you might for tomatoes. These nodes will produce roots, giving your plant access to more water and nutrients. Water deeply, right away, to help the soil settle, removing air pockets, and keeping the roots moist. And be sure to label your plants! All peppers are self-pollinating, but crops are significantly larger when other pepper plants are nearby. Note: if you plan on saving seeds from your hot peppers, be sure to keep different varieties away from each other, as they will cross-pollinate.
Caring for hot pepper plants
Pepper plants benefit from a thick layer of organic mulch placed around, but not touching, each plant. Use a hose to water your plants thoroughly, at first. This will help the soil settle and keep the plants well hydrated. Once the roots take hold, you can use drip irrigation or a soaker hose. Plants should be side-dressed with nitrogen about once a month for healthy leaf growth. In August, you can increase feedings to once every two weeks. As fruit begins to mature, you can increase their hotness by only watering once a week and allowing the soil to dry out between waterings.
Harvesting hot peppers
Each pepper has a color that indicates it is ready to be picked. Read your seed packet or check online or at your local library to learn more about your specific varieties. Many peppers are harvested while immature, the flavor actually becomes sweeter as the fruits mature.
Pepper pests and diseases
Pepper weevils, cutworms, aphids, armyworms, flea beetles, leafminers, corn earworm, leafrollers, nematodes, weevils, thrips, spider mites, tomato psyllids, and whiteflies can all become pepper plant pests, though I have rarely had any serious problems here in the Bay Area. I have found that birds are more likely to become a problem. Most pepper diseases are of the fungal variety: powdery mildew, crown rot, root rot, verticillium wilt, and tomato spotted wilt are common with improper irrigation. Also bacterial spot, several mosaic viruses, blossom end rot, and curly top may occur. Sunburn, or sun scald, can also be a problem on pepper plants with insufficient leaf cover. Personally, I have had excellent results growing pepper plants under my fruit and nut trees.
Make a little space in your spring planting schedule to start some chili pepper plants for yourself and your friends!
I always assumed that groundcherries grew underground.
Having never eaten one or seen one, I decided to learn the truth about groundcherries.
Also known as Inca berries, golden berries, and Cape gooseberries, groundcherries are not gooseberries at all. Like tomatoes, however, they are berries. Members of the nightshade family, groundcherries are cousin to tomatoes, potatoes, and eggplant, but most people say they taste more like strawberries or pineapple.
Groundcherries (Physalis) get their Latin name from the papery bladder that surrounds the fruit. This bladder is made from the calyx. [The calyx is the green sepals that form around the base of a flower.] The common name refers to the way fruits are harvested, once they fall to the ground. There are over 75 species, all of which are native to the tropical Americas, including tomatillo (P. philadelphica). There are both edible and inedible members of Physalis. Inedible ground cherries are considered weeds.
Groundcherry plants look very much like tomato plants, but the stems are sturdier. The leaves can be oval, triangular, or lance-shaped. Like other nightshade plants, the bell-shaped flowers have five petals, with yellow, green, white, or purple centers. These bushy plants are often grown as annuals, but can be perennial, under the right conditions. The fruit is the size of a cherry and can be orange, green, yellow, or purple, with a structure much like tomatoes.
Chinese lantern (Physalis alkekengi) is an ornamental, inedible groundcherry that can become invasive. There is some talk about certain groundcherry species being toxic, but research has not consistently shown this to be true. More research is being done, mostly because there is a lot of debate about the different groundcherry species.
How to grow groundcherries
If you can grow tomatoes, you can grow groundcherries. These plants like a lot of sunshine and hot temperatures, which makes them well suited to the South Bay Area. Also, it performs well in poor soil and can be grown in containers. Start seeds in small pots 6 to 8 weeks before the last frost date, planting them 1/4 inch deep. Keep the soil moist. Seeds should germinate in 7 to 10 days. Like tomatoes, groundcherries will sprout roots from their stems, so seedlings should be planted deep enough to bury the first or second stems, after plants have been hardened off. This will give your groundcherry plants a better root system. These plants get bushy, like tomatoes, so be sure to give each plant the room it is going to need. Plants should be at least two feet apart. Irrigate regularly and be sure to top dress around the plants with aged compost. Groundcherries are heavy feeders.
Groundcherry pests and diseases
Like their cousin, the tomato, groundcherries are susceptible to aphids, spider mites, whiteflies, hornworms, cabbage loopers, flea beetles, nematodes, cutworms, stinkbugs, and slugs. Many of these pests can be thwarted with row covers. Groundcherries are resistant to many diseases, but they may be affected by verticillium wilt, fusarium wilt, curly top, tobacco mosaic virus, and alternaria.
Immature fruits are not edible. After the husks have dried and become papery, the fruit will drop to the ground. This is the fruit you should harvest. The husk is not edible and should be added to the compost pile. Groundcherries are commonly eaten fresh, or used to make jams, jellies, sauces, and pies. The fruit can also be dried like a raisin, or used in salads.
Once you have grown groundcherries in your foodscape, it is not uncommon to find them growing on their own the next summer. Birds may eat a fruit, dropping the seeds where they will, complete with its own fertilizer packet.
These tiny packets of sweet, fruity flavor are a delight!
Eggplant is a tasty member of the nightshade family.
Cousin to tomatoes, potatoes, peppers, and tobacco, eggplant (Solanum melongena) grown in tropical areas is a perennial. Here in San Jose, California, it tends to be a large annual. Your eggplant bush can grow to be 5 feet tall, but most are closer to 2 feet tall.
Botanically, an eggplant is a berry. This is because it is a fleshy fruit, without a stone, that grows from a single ovary. Within that fleshy fruit are many tiny black seeds. These seeds taste bitter because they contain nicotine alkaloids. Don’t worry, though. You would have to eat 20 to 40 pounds of eggplant to get the equivalent nicotine found in one cigarette.
How to grow eggplant
People have been growing eggplant since prehistoric times. It’s that easy. Originally from Asia, eggplant needs heat. Seeds can be started indoors a month before your last frost date. The seeds are small, so do not plant more than 1/4 inch deep. With plenty of heat and moisture, your seeds may germinate in as little as 7 days. Be sure to harden off your plants before installing them outside. They will need a spot with plenty of sun and good drainage. Eggplant prefers slightly acidic soil (pH 5.5 to 7.0), so acidification may be necessary here in the Bay Area. Plants should be spaced 18 to 24 inches apart. They will need a lot of water and regular feeding. Reduce competition with weeds by mulching around plants. Eggplants are available in several different sizes, colors, shapes, and patterns, plus there are early maturing varieties. Give ‘em all a try!
Eggplant pests and diseases
Aphids, armyworms, thrips, cabbage loopers, flea beetles, nematodes, lygus bugs, and spider mites will all want to feed on your eggplant plants. Damping off, mosaic, root rot, tomato spotted wilt, foamy canker, and verticillium wilt are common eggplant diseases. Eggplants are also susceptible to a condition called ‘shoe stringing’. Shoe stringing describes the way leaves become thin and leathery, with a chewed up appearance. The cause is unknown at this time.
Your eggplants are ready to harvest when the flesh does not spring back when pressed. Do not pull or twist fruit to remove it - this can damage plants. Instead, snip the stem just above the fruit. Eggplants have the best flavor when they are eaten within 24 hours of being picked. And they are best left on the kitchen counter and not in the refrigerator.
According to 13th century Italian folklore, eating an eggplant can make you go crazy. That claim was repeated in 19th century Egypt, when it was said that insanity was "more common and more violent" when the eggplant is in season in the summer. (Wikipedia)
There are many theories about the insanity claim. Personally, I think it may have something to do with the abundance of food your eggplant plants can produce.
Tomatillo plants are free spirits and they make delicious salsa verde!
Unlike most other agricultural plants, tomatillo plants refuse to be hybridized. This is pretty surprising, since recent research has shown that tomatillos have been around for 52 million years! They have retained their wild nature while still providing us with an easy to grow edible plant. These members of the nightshade family (Solanaceae), are cousin to tomatoes, potatoes, peppers, eggplant, and tobacco. As such, you should not eat any part of the plant other than the fruit.
Tomatillo fruits are greenish and sticky. They come wrapped in their own natural paper husks. The plants, being wild by nature, can take on a variety of shapes and sizes, but they tend to be low-growing, sprawling plants. If you want something really unique, you can even find purple tomatillos! Tomatillos are one type of ground cherry, but there are many others.
How to grow tomatillos
Native to Mexico, tomatillos (Physalis philadelphica), also known as Mexican husk tomatoes, prefer bright, sunny locations and they are somewhat drought tolerant. They grow best in nutrient rich soil with a neutral pH. Adding compost to the bed before planting will help give your tomatillos a head start. The plants grow quickly, but they take a long time to produce fruit (60 to 80 days). Tomatillos are not self-fertilizing, so you will need multiple plants to get a crop. Seeds should be planted 1/8 to 1/4 inch deep. Tomatillos can be grown in large containers (at least 5 gallons) but they need more sunlight than a window garden can provide. Like peppers, tomatillo seeds need warm temperatures to germinate.
If you buy tomatillo seedlings, plant two-thirds of the stem below ground, as you would for tomatoes. All those nodes will covert to root tissue, helping your new plants get a better start and produce a bigger harvest. Place mature plants three feet apart and provide support with trellising or tomato cages. Like tomatoes, you will want to keep the soil around your tomatillos moist, but not soggy. Mulching can reduce evaporation and competition from weeds. It also stabilizes soil temperatures.
Tomatillo pests and diseases
Being relatively wild, tomatillos are pretty rugged. Fungal diseases, such as powdery mildew, can occur if plants are left to sprawl on the ground, which is why providing support is a good idea. Flea beetles may also chew holes in the fruit.
Harvesting and storing tomatillos
Tomatillos stay greenish, so color will not tell you when it is time to harvest your tomatillo crop. Instead, watch to see when the fruit has filled its husk to bursting. If the fruit is left to ripen further, it will turn yellow or purple, but it won’t taste as good. Once your tomatillos are picked, you can store them in a paper bag in the refrigerator for 2 or 3 weeks, or you can make your own salsa verde and do some canning!
Sweet or hot, bell-shaped or elongate, all peppers are members of the nightshade family.
People have been growing peppers for several thousand years. Native to the Americas, peppers (Capsicum) are now grown all around the world. The popular spice, paprika, is made from several different types of peppers.
All peppers are self-pollinating, but crops are significantly larger when other pepper plants are nearby.
Hot peppers and the Scoville scale
Hot peppers are rated using the Scoville scale. Scoville heat units (SHU) are a function of the amount of capsaicin found in the fruit. For comparison, pepper spray used by law enforcement can have 500,000 to 1 million SHUs and sweet bell peppers have a Scoville rating of zero. Here are some common peppers and their Scoville ratings:
Choose your peppers accordingly (and be sure to wash your hands after handling hot peppers and their seeds before you do ANYTHING else). Seriously.
How to grow peppers
Peppers love warm weather. In fact, there’s no sense starting pepper seeds early, because they won’t germinate. Even if they do, they won’t grow well. To get a head start on the growing season, many gardeners use seed heating mats. The soil needs to be 70 to 84 °F for peppers to really get going. Peppers prefer loose, loamy soil (or even sand), so you may want to grow them in raised beds or containers. Seeds should be planted 1/4 inch deep. Ultimately, you will want to place plants 18 to 24 inches apart. When thinning, snip unwanted plants off at soil level to avoid disturbing other plants’ roots. At first, the soil should be kept moist but not soggy. Soggy soil can cause damping-off disease and several other problems.
Pepper pests and diseases
Like many other of our favorite food plants, peppers are in big demand in the insect world. Cutworms, aphids, armyworms, flea beetles, mites, leafminers, thrips, corn earworm, leafrollers, nematodes, weevils,spider tomato psyllids, and whiteflies should be watched for, and some birds may want to take a bite, as well.
Fresh-from-the-garden, sweet, sun-warmed, juicy tomatoes are probably the number one reason why people start gardening. Be forewarned! No store-bought cousin will ever measure up once you have experienced the real deal!
Native to South and Central America, tomatoes have been cultivated for over 3,000 years. Prior to Halloween of 1548, Italy had no tomato sauce. It’s hard to imagine, isn’t it? Now, as winter fades, many gardeners feel compelled to plant tomatoes. While starting too soon is a waste of time and seeds, tomatoes can be started indoors 6 to 8 weeks before the last frost date.
Commonly grown as annuals, tomatoes (Solanum lycopersicum) are actually perennial plants, in their native regions. These members of the nightshade family, along with eggplants and potatoes, are self-pollinating. This means that honey bees and other pollinators can carry pollen from one flower to another, on the same plant, to cause a plant to create fruit. Of course, the more plants you have, the higher your pollination rates will be. Plus, you can never have too many tomatoes, right?
Shopping for tomato plants
Spring garden shows and plant sales draw gardeners like moths to flame. This is especially true about tomatoes. With so many varieties, colors, and sizes to choose from, we tend to get carried away. To be fair, who doesn’t want to try growing that new black, striped, pear-shaped variety with a nice citrusy aftertaste? So, we fill boxes, bags, and the backseat with countless new and old favorite tomato plants and head home. Very often, those store-bought tomato plants are root bound. If you buy tomato seedlings, be sure to handle the plants gently as you transition them from greenhouse city life to life in your yard. Also, as dreams of heirlooms and hybrids dance through your head, remember that tomatoes, like all other plants, can be vectors for pests or disease. When you bring new plants home, be sure to place them in a quarantine area until you are sure they are healthy.
What is your tomato type?
Tomato plants are classified as either determinate or indeterminate. Determinate plants, also called ‘bush’ tomatoes, look like 3 to 5-foot shrubs and all the tomatoes ripen within a 4 to 6 week period. This is perfect if you plan on canning your bounty. It doesn’t really work if you are growing tomatoes for fresh eating. Indeterminate tomatoes put out a continuous crop all summer and fall, providing a similar sized crop, but spread out over time. You can also check the UC Davis chart on tomato varieties, if you are growing in California.
How to grow tomatoes
Tomatoes are easily grown from seed or cuttings. They grow best in the ground, but can also be grown in containers or straw bales. Seeds should be planted 1/4” deep. Keep the soil moist, but not soggy. As seedlings emerge, they can be hardened off and moved outdoors, as long as they are protected from chilly nights and strong winds. Germination of most tomato seeds usually takes 5 to 10 days in warm weather. Colder temperatures slow the process. Give your tomato seedlings a boost with fish emulsion. Keep weeds away from your seedlings, so that they can get a healthy start. As your tomato plants get bigger, you may want to provide some support with tomato cages or stakes.
Pinching your tomato plants
No, I don’t want you to be mean to them - well, maybe a little. Pinching back excess growth can make more nutrients available to whatever is left, plus it stimulates flower and fruit production. On the other hand, if you take away too many leaves, your tomatoes can get sunburned. Yellow or green shoulders on otherwise red fruit is also a sign of too much sun exposure. Pruning tomatoes is a balancing act between sun protection, fruit production, and disease prevention. Deficit irrigation can also be used to significantly improve the flavor and increase the sweetness of your homegrown tomatoes.
Prune your tomato plants so that they have two or more stems starting near the base of the plant. If you pinch your plants to make a central stem, they will produce fruit earlier, but at lower quantities.
Tomato pests & diseases
Hornworms and blossom end rot are the two most common problems faced by California tomato growers. Blossom end rot is caused by an erratic calcium supply, which occurs whenever watering is irregular. A regular watering schedule can reduce blossom end rot in tomatoes, as well as leaf roll, cracked fruit and catfacing, and citrus fruit split. Tomato hornworms are large and can devour an amazing amount of foliage before you even know it. Achemon sphinx moths look a lot like tomato hornworms, but they are mostly limited to grape vines.
Other common tomato pests include tomato fruitworms, tomato pinworms, Eriophyid mites, bagrada bugs, blister mites, green fruit beetles, Japanese beetles, nematodes, leaf-footed bugs, leaf miners, oriental fruit flies, stinkbugs, spider mites, whiteflies, treehoppers, weevils, cutworms, and voles. And squirrels. Always squirrels.
Tomato diseases include tomato ringspot, tomato spotted wilt, alternaria stem canker, fusarium wilt, tobacco mosaic virus (TMV), grey leaf spot, anthracnose, verticillium wilt, stem blight, and powdery mildew. Many of these diseases can be prevented with regular crop rotation.
Tomatoes grown from seed will develop a taproot. What is really strange is that tomatoes grown from cuttings will not.
If we ever meet in person, be sure to ask me about Wally's s****y tomatoes!
Adding sweet potatoes to your garden or landscape provides many years of heat tolerant foliage and delicious edibles. Sweet potatoes are referred to as a ‘long crop’ because they take 3 to 5 months to produce, but this durable perennial is a good investment of your garden space. Did you know that the leaves of sweet potato plants are edible? Read on!
Personally, I’ve always enjoyed a baked sweet potato with just a little butter and salt. They are so sweet all on their own, they really don’t need much else. Others prefer them sprinkled with brown sugar, or, in the Turkey Day favorite, covered with a layer of mini marshmallows. What I didn’t realize until recently, is just how easy sweet potatoes are to grow, especially in the hot summers that frequent San Jose, California.
Sweet potatoes v. yams
Before we get too in-depth, let's make sure we know the difference between sweet potatoes and yams. If you live in the U.S., you’ve probably never had a yam. Yams are from Africa and they can grow up to 6 feet in length and weigh in at as much as 150 pounds! Yams tend to be starchy and they need to be cooked before they are eaten, to get rid of toxins. Sweet potatoes (Ipomoea batatas) are an entirely different critter. Sweet potatoes are from tropical South America, they tend to be sweet, and are significantly smaller than yams. The whole sweet potato/yam confusion began in the U.S. because sweet potatoes have two different growth varieties: firm and soft. Firm sweet potatoes were sold first, then the softer variety arrived. To differentiate them from their firmer brethren, soft sweet potatoes were called yams. Nutritionally, sweet potatoes far surpass yams. If you are going to invest space, water, and time: grow sweet potatoes. Here’s how.
How to grow sweet potatoes
Sweet potatoes love hot summers. These herbaceous perennial vines need only 30-39 inches of rainfall (or irrigation) a year and they prefer temperatures in the 75 to 95-degree F range. Sweet potatoes prefer loamy soil with a pH between 5.0 and 6.2. This is more acidic than we tend to have in the Bay Area, but, like regular potatoes, sweet potatoes are easily grown in large containers, so soil pH adjustments are relatively easy. Simply add an acidifier to the soil mix at planting time. Sweet potatoes are started from transplants and vine cuttings. These cuttings are called ‘slips’. While it may be tempting to use grocery store sweet potatoes to start your crop, this is not a good idea. First, many growers treat store-bound produce with growth inhibitors. Plus, you have no way of knowing if your grocery store sweet potato is carrying pests or diseases that can compromise your soil for a very long time. It really isn’t worth the risk. Invest in sweet potato plants or bare root slips from reputable suppliers. The plants will last a long time and are worth the investment. Plants prefer full sun and should be installed in early spring. Plants should be placed in large containers or in hills that are one foot high and 3 feet apart. Cover the roots with soil but leave the stem above ground and water lightly. Mature plants only grow about a foot tall, but can spread 3 or 4 feet, so plan accordingly. Being highly frost sensitive, plants may need protection in winter.
Sweet potato pests & diseases
Like regular potatoes, sweet potatoes are susceptible to many fungal diseases, so be sure your plants never sit in water or soggy soil for long. Common diseases include crown gall, bacterial wilt, Alternaria, Anthracnose, Fusarium wilt, grey mold, rust, root knot, and root rot. Weevils, aphids, flea beetles, leafhoppers, and wireworms are the most frequent sweet potato pests.
Sweet potato trivia
Regular potatoes are underground stem tubers, while sweet potatoes and yams are actual root vegetables, like carrots and beets, in that they store reserve energy in root tubers. It doesn’t mean much in the kitchen or even in the garden, but botanists swear by these differences. In fact, if you have ever used beaters to whip up a batch of mashed sweet potatoes, you probably found a bunch of fibers wrapped around the beaters. Those fibers are vascular tissues! Also, like legumes, pineapple, mango, and sweet sorghum, sweet potatoes have evolved alongside a helpful bacteria (Gluconacetobacter diazotrophicus) that fixes atmospheric nitrogen, making it available to the plant.
Harvesting & curing sweet potatoes
Small sweet potatoes can be harvested and used at any time. Full-sized roots are harvested in fall. After carefully removing them from their hills (hopefully without causing them any damage), they should be placed in a warm, dry location for 8 to 10 days. This helps toughen the skin for better storage and heal any wounds. Stored properly, sweet potatoes can be held for several months.
You can find a nice read about sweet potatoes where "botany meets the cutting board" at the Botanist in the Kitchen.
No, deficit irrigation doesn't refer to tossing the national budget into the ocean.
Instead, it is a method used by growers to increase the amount of sugar in foods such as tomatoes, basil, pomegranates, and peaches.
Plants have flavor because they contain sugar and volatile chemicals. Aroma plays a major role, as well, but we will leave that for another day. The volatile chemicals that generate flavor are used by plants as defense mechanisms. The pungent taste of many herbs is a perfect example of strong flavors being used to discourage herbivore and insect feeding. As water levels within a plant are reduced, those flavors get stronger. This is where deficit irrigation comes in.
The opposite of dilution
When the water supply is significantly reduced, sugar and flavor molecules become concentrated. More water means less sugar and flavor per plant, while less water means more flavor. It's a simple matter of dilution.
Some crops are bad choices for deficit irrigation. Cucumbers, melons, and other members of the squash family are more likely to turn bitter than better without adequate irrigation. For crops well suited to this practice, there is still a downside. Improperly done, deficit irrigation increases the risk of stunted growth and smaller fruit. Start too early and you end up with fruits and vegetables that are weaker, drier, and not what you were hoping for.
In the case of backyard tomatoes, it's a good idea to significantly reduce watering as the fruit begins to turn red. This way, the size is already reached and flavor is in full production.
Deficit irrigation also helps conserve precious water resources.
You can grow a surprising amount of food in your own yard. Ask me how!
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