Tomatoes
Homegrown tomatoes cure all that ail me.
Tomatoes are the most popular vegetable grown by the home gardener, but growing them can be a challenge. See how to plant and care for them, as well as how to recognize common problems and pitfalls!
Also see how to Plant Too Tall Tomatoes.
Tomatoes need at least 6 hours of direct, unimpeded sunlight. Morning sun is better than afternoon sun. Avoid planting members of the tomato family – tomatoes, potatoes, peppers, and eggplant – in the same area for two to three years as they share the same pests and diseases, and these problems build up after repeated growing in the same area.
Creating the richest soil possible is the greatest key to success. Whether the soil is sandy, clayey, or somewhere in between, add a good quality non-manure based compost. Tomatoes are very susceptible to herbicide damage which can be introduced through contaminated manure based compost or by application ‘weed and feed’ products. Mix in enough compost such that the garden is approximately 50% compost and 50% soil. If the soil is too shallow, build a raised bed using a quality prepared soil.
For a large crop of tomatoes that all ripen at the same time, choose determinate varieties. These are a good option when canning tomatoes.
For plants that begin producing once they achieve maturity, and keep producing as long as conditions allow, choose indeterminate varieties.
The Natural Gardener carries many varieties that are well adapted to the Central Texas region. It is important to grow varieties that are fairly quick to mature. Varieties that ripen in 73 days or less are recommended. Also, some varieties have been bred to be resistant to common diseases. If disease has been an issue in the past, choose varieties with the most resistance. Here is the guide to disease resistance codes found on our plant labels:
- A = Alternaria
- F = Fusarium (FF = both Fusarium race 1 and 2)
- N = Nematodes
- T = Tobacco Mosaic Virus
- V = Verticillium
Tomatoes are harmed by temperatures below 45º F, and won’t set fruit above 90º, so timing is crucial. Spring tomatoes can be planted in the ground just after the average last frost date (at Austin Bergstrom, it’s March 3), but will need to be protected from cool/cold temps. Use row cover, a sheet, blanket, or plastic for frost protection. Do not allow the cover to touch the plant, or that part will freeze. Be sure to cover the plant completely, bringing the cover all the way to the ground. If using plastic and it gets warm and/or sunny the next day, remove the plastic or the plants will overheat. To get a head start on the season, plant tomatoes in a container first and bring indoors when cool temperatures threaten. For in ground tomatoes try Planting in a Well.
In July, if spring-planted, indeterminate tomatoes still look good, cut off 2/3 or more of the plant and they will be rejuvenated for the fall season. If not, acquire fresh tomato starts and plant again for a fall crop of tomatoes. Now, it’s a race against time to get ripe tomatoes before the first frost. At Austin Bergstrom, the average first frost is November 28. Incandescent Christmas lights or utility lights can be used under frost protection covers to provide a gentle source of heat. If that is not convenient, harvest all green tomatoes before the first frost and let them ripen on a windowsill.
Tomatoes are the only vegetable which can be planted with its stem buried deep in the ground. Remove the bottom leaves and leave 4-6” of stem above ground; the buried section of stem will sprout roots! Be sure to give plants the correct spacing, based on the variety. See more on Planting Too Tall Tomatoes.
Water the plant thoroughly right away with seaweed and fish emulsion. This is a great stimulator for new transplants. Most varieties, except ‘Patio,’ will need a tomato cage or plant stakes – the sooner, the better. Apply mulch, about 2-3” deep. Mulch holds in moisture, keeps out weeds, moderates soil temperature, and can help prevent diseases by preventing rain from splashing soil up on the plants.
Keep the soil deeply and evenly moist throughout the growing season. Over or under-watering can lead to cracks developing in the fruit and to a condition known as Blossom End Rot.
Tomatoes are heavy feeders! Add a dry fertilizer every 4 – 6 weeks as well as applying a liquid seaweed and/or fish emulsion up to every week. For the first couple of dry fertilizer applications, use a high nitrogen fertilizer to grow the plant large and leafy. Afterwards, switch to a high phosphorus fertilizer to encourage the mature plant to set and develop fruit.
Regular foliar feeding with seaweed and/or fish fertilizer strengthens the plant, builds its resistance to diseases and pests, and provides essential trace minerals. Seaweed also contains growth stimulants that can help boost all plant functions, including flowering and fruit set. Foliar feed only in early morning or late evening, when there is adequate moisture in the soil. Also, avoid pruning tomatoes, since an abundance of leaf cover protects tomato fruits from sunburn. In summer, 40% shade cloth suspended over tomatoes, or on the west side, can also help.
Tomatoes are susceptible to a host of insect and disease pests. Follow the recommendations listed will help to ensure stress to the tomato plant is minimized, reducing its vulnerability to such problems. If problems begin to occur, get an accurate diagnosis as soon as possible.
Bacterial and Fungal Diseases – Many soil-borne diseases, such as Fusarium and Phytophthora, can be prevented by mixing beneficial streptomyces (such as Actinovate) into the soil at planting time. This is crucial if tomatoes must be planted in the same place as last year. If these diseases – and even air-borne diseases – show up on plants after planting, a water-soluble version can be used as a curative. There are a number of different products that utilize beneficial bacteria to control plant fungal and bacterial diseases. Monterey Disease Control is a product which works well on early blight, one of the most common fungal pathogens on tomatoes.
Spider Mites – This common pest of tomatoes needs to be treated right away. Spider mites are tiny insects that live on the surface of the leaves, sucking juices, which causes the leaves to yellow or develop pale freckles. In advanced stages, webbing will develop. Spray horticultural oil (only if temps are BELOW 85°F) or insecticidal soap once a week for two or three weeks in a row.
Aphids – These small, soft-bodied, sucking insects that cluster on leaves and stems. They may be black, white, green, yellow, or red. To control, start with a strong blast of water every day. For a more serious case, spray plants with insecticidal soap every 5 days until controlled.
Tomato Hornworm – This and other caterpillars may cause leaves to disappear overnight. Spray leaves in the evening with B.t. (Bacillus thuringensis) for treatment. Likewise, if there is a small, neat hole in the fruit, it may be a tomato fruit worm, and B.t. will help prevent further damage.
Birds and Stink Bugs – Both are very difficult to thwart. Leaf-footed bugs and other stink bugs may be picked off by hand and dropped into a bucket of soapy water, or sucked away with a shop vac or dust buster. Dust diatomaceous earth (DE) over the whole plant to help reduce numbers. If tomato fruits have messy, rough holes in them, it is probably bird damage. Before the first fruit ripens, hang red Christmas ornaments to fool and frustrate birds. Shiny objects such as old CDs or holographic scare tape can also act as deterrents.
Blossom-End Rot – This condition is not caused by a disease or an insect. This dry, brown/black lesion on the bottom of the fruit is a calcium deficiency usually triggered by uneven watering, so remember to water deeply and infrequently, and to mulch around the plants to prevent rapid moisture loss. In containers, the addition of a calcium supplement such as bone meal or crab shell, can help to alleviate the problem.
- What does it mean if a tomato is a hybrid, open pollinated, or an heirloom?
- Hybrid – a commercial variety that won’t come true from seed. It’s an “arranged marriage” between two different varieties, similar to how a labradoodle is a cross between a labrador and a poodle. Breeding two labs will produce more labs, and breeding two poodles will produce more poodles; but breeding two labradoodles will result not in more labradoodles, but rather, a litter of puppies that have traits of both original grandparents. It is NOT the same as genetically modified.
- Open-Pollinated (OP) – a variety is one that breeds true from seed, meaning the seed saved from the parent plant will grow offspring with the same characteristics. OP seed is produced by allowing a natural flow of pollen between different plants of the same variety.
- Heirloom – varieties that are OP with a long history of being cultivated and saved within a family or group. They have evolved by natural or human selection over time. Some popular heirloom varieties include Brandywine, Amish Paste, and Black Cherry.
- What tomatoes are good for growing in containers?
- Look for bush varieties, and especially the Patio variety which was bred specifically for pot growing.
- What is the most heat tolerant type?
- Big slicers can’t set fruit if temps are too hot (consistently above 72 at night or 92 during the day), but cherries varieties don’t seem to have that problem. Some heat tolerant slicers bred in Texas (Porter, Rutgers) or Florida (Solar Fire, Homestead) may set fruit an extra week or two longer than other types, as do the heirlooms Arkansas Traveler and Hillbilly Potato Leaf.
- What is the best producer?
- Cherries, because they can produce through the heat while others can’t.
- When should I plant?
- Tomatoes are killed by frost, but they may not have time to set fruit before the summer heat if planted when all danger of frost is past. When planted early, they will need protection until night time temperatures are in the 50s, and again in case of late frost, but will also have time to mature and set fruit. Tomatoes can also be planted in July for a fall crop.
- What varieties does The Natural Gardener recommend?
- Cherries – Sungold, Juliet, Sweet 100, Sweet Million, Large Red Cherry, Yellow Pear
- Paste (for sauces/canning) – Roma, San Marzano
- Slicers (heirloom) – Cherokee Purple, Black Krim, Green Zebra, Brandywine (pink isn’t a good producer, red is), Hillbilly Potato Leaf, Mortgage Lifter
- Slicers (hybrid) – Celebrity, Early Girl, Big Boy, Better Boy, Super Fantastic
