Fresh-from-the-garden, sun-warmed, sweet, 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 use 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, it will produce fruit earlier, but at lower quantities. Use this image to help you pinch back your tomatoes properly:
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, 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 ring spot, 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’s 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!
We’ve all heard some seeds or plants described as heirlooms and others hybrids, but what do those terms really mean?
Both hybrids and heirlooms come about through naturally occurring cross-pollination, as opposed to genetically modified organisms (GMOs), which are created in a lab using altered DNA strands. Personally, I think we are setting ourselves up for a Major Fail, messing with DNA that way. I do not use GMO seeds or plants in my garden or landscape.
[Did you know that some governments (the USA included) have passed laws making it illegal to save or share certain seeds harvested from plants grown at home? This is because some GMO and hybrid seeds have been patented by corporations.]
Before agriculture became an industry, people grow a wider variety of plants for food. That biodiversity helped offset inclement weather, diseases and pests, and other threats to a failed crop and the resulting starvation. Corporate agriculture, on the other hand, feeds countless millions by generating a smaller variety of uniform plants that consistently grow at specific rates, that can be sprayed with a variety of pesticides, herbicides, and fungicides, ship well, and store well. As many of you know, taste and texture often suffer s a result.
Pros & cons of heirlooms
Heirloom seeds are those that have been handed down, person to person, in a specific geographical region, for a very long time. Also, heirlooms are open-pollinated, which means pollination occurs naturally, by wind, birds, animals, and insects, and not by human efforts. Heirloom varieties are at least 50 years old (some say 100 years), and many of them have been grown consistently, in the same locale, since before WWII. These plants have evolved to take advantage of local microclimates and beneficial insects. Heirloom seeds are hand selected by gardeners from the very best plants each growing season. Many heirloom plants do not have the uniformity or long term storage capabilities of hybrids, but growers (myself included) claim that the flavor is significantly better. Heirloom crops have more variety in size and shape than hybrids, but they always grow true to their parent plants. Heirlooms are more genetically diverse, making them more durable as a species, and less susceptible to local pests and diseases. Heirloom offspring are fertile and can reproduce.
Pros & cons of hybrids
Hybrid plants are intentionally created by cross-pollinating different varieties of a species. The intention of hybridization is to take advantage of the best characteristics of each parent plant, creating what is known as hybrid vigor (heterosis). This vigor only lasts for one generation. Hybrid seeds do not grow true to their parents and they lack vigor and genetic diversity. This lack of diversity is what caused the Irish Potato Famine of the 1840s. If all the plants are identical, they are equally susceptible to pests and diseases. A single threat can be devastating.
Creating a hybrid that grows “true” to the desired characteristics takes years of diligent effort. Plants are often pollinated by hand or grown in greenhouses or pollination bags that block contamination from outside pollen to ensure that pollination only occurs between the desired plants. The majority of the fruits and vegetables you see in grocery stores are hybrids. Harvests are very consistent in size and shape. Hybridization is done for many specific characteristics:
When shopping for plants and seeds, one way to know if it is a hybrid is to look at the Latin name. If you see the letter “x” between words in the name, it is a hybrid. For example:
Raspberry (Rubus idaeus) crossed with blackberry (Rubus ursinus)
creates Loganberry (Rubus x loganobaccus)
*Check labels for the letters V, F, N, T or A. These symbols indicate a resistant to verticillium wilt, fusarium wilt, nematodes, tobacco mosaic virus or alternaria stem canker, respectively.
Understanding the difference between heirlooms and hybrids can help you make the right choice if you want to collect viable seeds from your harvest for next year’s planting.
Parsley - it’s not just for restaurants any more.
As a kid, I always turned a suspicious eye toward that sprig of greenery on my plate. My mother urged me to try it, so I did. Unfortunately, my young taste buds were not impressed. The mildly bitter bite of parsley was not my idea of delicious until many years later. Now that my taste buds are older and wiser, the refreshing tang of parsley adds a bright balance between flavors, cleanses the palette, and spices things up. If that weren’t reason enough to add parsley to a landscape, parsley packs one heck of a nutritional punch and, hey, it looks nice in the garden!
Parsley is a central Mediterranean plant, which means that it grows well in California, as long as it is protected from our scorching hot summers. Parsley makes an excellent shade garden or container plant. You can even grow it on your kitchen window sill for easy access and nice color if you have strong enough sunlight.
Parsley is related to celeriac and celery, which explains its Latin name (Petroselinum crispum), which means ‘rock celery’, but it’s a heck of a lot easier to grow than celery. Parsley prefers well-drained soil that is kept moist, but my plants seem to grow under just about any conditions. In spite of my heavy clay soil, I have several parsley plants that thrive under roses, trees, and shrubs. Research has shown that parsley also repels asparagus beetles, making it a good companion to asparagus and tomato plants.
Growing parsley does require some patience if you are starting from seed. Seeds should be planted 1/2 inch deep, 6 inches apart, and they can take 4 to 6 weeks to germinate. Germination rates are pretty high, so growing parsley from seed is the most cost effective method. While you’re at it, plant some extras and give young plants to family and friends as gifts!
In tropical areas, flat-leafed and curly parsley are grown as annual herbs. In more temperate regions like ours, parsley is biennial. Biennial plants take two years to go from seed to seed, but some of my parsley plants keep on growing for another year or so. In addition to leaf parsley, there is a variety called Hamburg root parsley (P. crispum radicosum). Root parsley is grown for the taproot, which looks, cooks, and eats like a white carrot. (I may have to try that!)
Parsley plants allowed to go to seed provide habitat, pollen, and nectar to honey bees and many other beneficial insets, some swallowtail butterflies, and even goldfinches.You will probably also end up with many free, randomly placed parsley plants next year!
If flavor and looks weren’t reason enough to grow your own parsley, the CDC says it’s a nutritional gold mine. They ranked parsley at #8 as a food that reduces chronic diseases, such as cancer, coronary disease, and osteoporosis. To learn more, check out the U.S. Dept. of Agriculture’s nutritional analysis website that allows you to look up the nutritional value of pretty much any food. Just 10 sprigs of parsley provides 22% of the RDA for Vitamin C and 200% of Vitamin K.
It’s pretty. It’s durable. It’s good for you. And it tastes good.
Where’s your parsley planted?
Blistered leaves and warty twigs are signs of eriophyid mites.
Eriophyid mites are a family of microscopic plant parasites that include blister mites, gall mites, bud mites, and rust mites. While you will probably never see them without a 20x hand lens, at 1/100” in length, they can be a translucent yellow, pink, white, or purple, with two pairs of legs up near the head.
Symptoms of eriophyid mite feeding include:
Blister mites commonly attack beech, boxelder, cottonwood, elm, maple, live oak, walnut, willow, poplar, roses, privet, and alder. Unfortunately, they also feed on tomatoes, peach, apples, pear, and grapes. I have also heard of them on plum trees in the Bay Area. Eriophyid mites spread on the wind, so there isn’t much you can do to stop them from showing up in your landscape. Luckily, the damage they cause is mostly aesthetic and poses no real threat to otherwise healthy plants. That being said, who wants warty leaves or scabby twigs? Also, eriophyid mites may also carry viruses that can cause real damage.
Insecticidal soaps and horticultural oils can be used on heavy infestations, but simply removing affected leaves, buds, flowers and twigs is really all that’s needed. Sulphur and neem oil have also been shown to be effective. Before you work too hard at getting rid of these minor pests, you may want to keep in mind that the eriophyid mite serves as a replacement food for predatory spider mites and other beneficials, when their foods of choice are absent.
Isn’t it nice to know that some problems in the garden are not big enough to worry about?
If you have citrus trees, you have leaf miners.
Leaf miners can be found feeding on many edible and ornamental plants, including tomatoes, beans, cole crops, cucurbits, aster, peas, impatiens, petunia and dahlia. While leaf miners are generally not a threat to plant health, they can detract from a plant’s appearance and it is still a good idea to monitor infestations.
Leaf miners are not a specific insect. Instead, they are the larval stage of several moths, sawflies and some beetles. The damage is distinct burrows within leaves, leaving what looks like serpentine, white trails. By feeding within the leaf, leaf miners are protected from predators and pesticides. In fact, applying pesticides actually helps leaf miners by killing off their predators. To make matters worse, all leaf miner species are resistant to carbamates, pyrethroids and organophosphate pesticides.
If you peel back the top layer of an infested leaf, you can actually see the pest, though you may need a magnifying glass.
You can minimize leaf miner damage by planting trap crops. Trap crops are preferred feeding plants. The most common trap crops are:
Also, do not prune unnecessarily, as this stimulates new growth which is more susceptible.
Spring is the time of year when it is common to see a white powder appear on the leaves of cucumber, melon and other cucurbits. You may also see it on tomatoes, roses, snapdragons, chrysanthemums, peas, artichoke, beets, grapes and practically everything else. This bane of gardeners is called powdery mildew.
What starts as a small white spot, powdery mildew expands to engulf an entire leaf as the nutrient-sucking fungi bleed the life from your garden. It can be found on either side of a leaf and sometimes on stems.
Powdery mildew is a fungus. It is caused by different types of fungi (e.g., Erysiphe spp., Sphaerotheca spp.), depending on which plant is affected. Contrary to common belief, moisture and humidity are not needed for these fungal beasties to appear.
Powdery mildew fungi simply need living plant tissue to survive and thrive. To make matters worse, their spores are carried on the wind, so the battle never ends. The reason powdery mildew seems to disappear in the heat of summer is that these microorganisms prefer shade and temperatures between 60° to 80°F. Our California summers are simply too hot for the spores to reproduce. Instead, they remain dormant until conditions improve.
The white powder seen on leaves is actually thin layers of fungal tissue (mycelium). Other symptoms of powdery mildew include:
Not only does powdery mildew cause leaf loss, it can also weaken a plant. This lowers production and increases susceptibility to other pests and diseases, such as Citrus Blast. Leaf drop can also lead to sunburn damage.
Prevention and vigilance are the best ways to counteract powdery mildew. These tips can help, but nothing will eliminate powdery mildew in the garden:
Now, some people recommend spraying plants with a baking soda and water spray. I have had mixed results, but other people swear by it.
Have the pea plants in your garden turned white?
If you look at the photo below, you will see that new (uninfected) growth is bright green, as it should be. Everything else on the plant looks bleached. That bleaching is caused by a fungal disease known as Fusarium wilt.
Similar to Verticillium wilt, Fusarium wilt is a common vascular disease in which a fungus (Fusarium oxysporum) clogs vascular vessels. It’s pretty much the coronary artery disease of the plant world. In addition to bleaching, common symptoms of Fusarium wilt include chlorosis, stunting, damping-off, brown veins, necrosis, and premature leaf drop.
This soil pathogen is found worldwide and it is spread by water splash, tools, and infected seeds and transplants. Fusarium wilt enters a healthy plant when germinating spores (mycelia) stab at the plant’s root tips and any damaged root tissue. That’s where the really amazing stuff starts to happen!
The Fusarium oxysporum fungus has no known sexual stage. Instead, it produces three different asexual spores: microconidia, macroconidia, and chlamydospores. Basically, the germinating spores (mycelia) inject themselves into a plant’s root system. From there, the mycelia move through the cells of the root cortex and into the xylem (a plant vein). Then, it starts producing the microconidia (asexual spores). The microconidia join the sap stream for a free ride to the rest of the plant. Eventually, there are so many microconidia that a vein is blocked. That’s when they germinate.
The vein blockage stops the plant form absorbing and moving nutrients, so the stomas close, the leaves wilt, everything looks bleached and it dies. As the plant dies, the fungus spreads throughout the plant and sporulates. [Cool word, right? It means “to produce spores”]
Fusarium wilt attacks a variety of garden plants and the pathogens are specialized according to the victim. Fusarium wilt can attack peas, beans, and other legumes, tomatoes, tobacco, sweet potatoes, cucumber and other cucurbits, and even banana trees!
Once a plant is infected with Fusarium wilt, there is nothing to be done except remove the plant and toss it in the trash. Planting resistant varieties in the garden can help prevent Fusarium wilt, and crop rotation is not an effective control method. This is because the chlamydospores can hang out in the soil for a long time. Some fungicides can be marginally effective.
Since Fusarium oxysporum prefers heavy, moist soil, aeration and adding compost to the garden can bring more oxygen into the soil. This reduces the welcome mat effect for many types of fungus. Ensuring proper drainage is the best way to avoid this garden menace.
Stinkbugs can destroy your garden in short order and they smell pretty bad!
Stinkbugs are true bugs, which means they are members of the Hemiptera family. The word Hemiptera comes the Greek for half-wing. The front half of their wings are hard and the back half are soft. Stinkbugs can be recognized easily because of their flattened, boxy, shield-shaped body and tiny scent gland openings near where their shoulder blades would be if they were human. The Green Stinkbug (Acrosternum hilare) is bright green with red, orange or yellow edges. Harlequin bugs (Murgantia histrionica) are shiny black with yellow, orange, and red markings.
Stinkbug eggs are laid in clusters of tiny barrel shapes on the underside of leaves in spring and fall. Before hatching, the eggs can be white, yellow, green, buff or even pink. When they hatch, the cluster will be covered with tiny brownish-orange babies, called first instar nymphs. Each instar is a developmental stage that is achieved through molting. Stinkbugs have five installs before reaching full size. Stinkbugs can have 4 generations every year and each female can lay hundreds of eggs at each laying. Yup, they add up fast!
There are 250 varieties of stinkbugs in the U.S. and 4700 worldwide. They can be brown or green. Stinkbugs eat seeds, grain, fruit, vegetables, ornamental plants, legumes, weeds and tree leaves. They can also transmit tomato bacterial spot with piercing mouthparts. Unfortunately, insecticides don't seem to have an effect.
Wasps and flies, such as the tachinid fly (Trichopoda pennipes) and the Trissolcus basalis wasp will parasitize the eggs, but those critters are not always available when you need them. You can also provide habitat for birds, spiders, toads, and other insect eating critters. The best method of control for stinkbugs is to handpick and deposit them in a container of soapy water or feed them to your chickens!
The Oriental Fruit Fly has been found in Cupertino, Los Altos Hills and the City of Los Altos. If you live within the quarantine area, DO NOT move fruits or vegetables off of your property.
The Oriental Fruit Fly tends to be bright yellow with a dark T-shape on its abdomen with clear wings. It is larger than a house fly, approximately 1/3" in length. It is a common pest in Asia and enters the U.S. through produce smuggled into the country.
Visit the Dept. of Agriculture’s Oriental Fruit Fly page to see the quarantine map.
I was surprised to see my containerized tomatoes starting to look like apple dolls. You know, those wrinkled up faces made out of withered apples ~ certainly not very appetizing!
When a plant is severely root bound, it may be necessary to cut the ring formation to encourage outward growth. To do this, use a sharp knife and cut vertical lines up the side of the root ball in several places. You only need to go in an inch or so. Using your fingers, pull the bottom roots outward as you place the plant in new soil.
Be sure to water well and your plants will grow new roots to support delicious above-ground growth!
You may have recently spotted (or heard) a large metallic green bug buzzing around your yard. Green fruit beetles, or figeater beetles, are large, clumsy, metallic green pests.
My dogs and chickens love to chase green fruit beetles, and I am grateful. In the heat of summer, these pests fly in to lay eggs throughout my garden and landscape, taking a toll on my fig harvest. They also feed on apricots, nectarines, plums, grapes, pears, and tomatoes, as well as manure and compost. Generally, figeater beetles (Cotinis mutabilis), do not cause a lot of damage, but they can if enough of them converge on your garden.
Green fruit beetle controls
Since these pests are attracted to the smell of ripe fruit, harvest frequently. Also, you can plant crops that ripen earlier in the season to avoid feeding green fruit beetles. Personally, I have trained my dogs to catch them and I use a butterfly net to pin them down, then I feed them to my chickens, but you may not have that option. Luckily, it is very easy to build a green fruit beetle trap. Simply mix 1 part water with 1 part grape or peach juice and put it in a one-gallon container. Then, create a funnel out of screen or hardware cloth and insert it into the container. The adult beetles will be attracted to the juice, climb down into the container, and then be unable to figure out how to escape. (I wonder how chickens feel about beetles drowned in juice…)
Have you noticed fine webbing on your tomato plants recently? Are your leaves looking stippled (spotted white or yellow)? If so, you are like the many other gardeners experiencing spider mites in their garden.
Spider mites are very tiny. The females are only 1/20” and the males are even smaller! However, as spider mites colonize on a plant, you will see webbing, especially on the underside of the leaves. Spider mites can suck the life juices right out of your favorite heirloom tomato and these little buggers can complete an entire generation in less than a week! Unfortunately, drought-stressed plants are more susceptible to spider mite infestations.
One of the most common causes of spider mite infestations is the use of broad spectrum insecticides, which kill off benficial predators along with the pests. The easiest (and least destructive) way to get rid of spider mites is to move the infested plant to a clear area of the yard and spray it off with the hose. Insecticidal soaps or horticultural oils can also be used, but watch out for applying them on sunny days. I recently learned the hard way that leaves will burn if insecticidal soap is left on the leaves during the heat of the day.
If spraying your plants does not provide adequate control, you can purchase western predatory mites and Phytoseiulus (spider mite predators). Spider mites love dusty conditions, so you can make your yard less hospitable by giving plants an occasional light rinse.
Blossom end rot is the bane of tomato growers. It starts as small brown spots on the bottom of the fruit and expands to a large, sunken brown or black leathery area.
The rotten part can be cut off and the rest of the fruit is fine for eating.
Yesterday, I curb-scored 8 very nice tomato cages. While they come in a variety of sizes and shapes, the most common type are concentric circles held at different heights, usually with three legs.
I hope this information inspires you to grow more of your own food. You can ask your garden questions on my Home page.