Solanaceae Annuals, Edible fruit, Vegetables

Sunset  – January 23, 2015

The tomato is an Andean native. Easy to grow and prolific, tomatoes are just about the most widely grown of all garden plants, edible or otherwise. Amateur and commercial growers have varying ideas about how best to raise them. If you’ve developed a successful method, continue to follow it. But if you’re a novice or are dissatisfied with previous attempts, you may find the following information useful.

Choose varieties suited to your climate that will yield the kind of crop you like on plants you can handle. Some varieties are determinate, others indeterminate. Determinate types are bushier, need little or no staking or trellising. Indeterminate ones are more vine-like, need more training, and generally bear over a longer period. (Though the plant sprawls and is incapable of climbing, you’ll often see it referred to as a vine.)

Plant a few each of early, midseason, and late varieties for longest possible production. (Or plant in spring and again in summer where growing season is long.) Typically, six plants can supply a family of four with enough fruit to enjoy fresh and to use for canning or sauce. Set out plants after frost danger is past and the soil has warmed. Most places, you can plant in April, May, or early June. But plant in February or early March in southwest desert Zones 12, 13; and in May or early June in cool-summer, short-season zones. You can also plant in fall in the tropical South; and year-round in most parts of Hawaii.

To grow tomatoes from seed, sow seeds in pots of light soil mix 5 to 7 weeks before you intend to set out plants. Cover seeds with 1/2 in. of fine soil; firm soil over seeds and keep surface damp.

Place seed container in cold frame or sunny window—a temperature of 65° to 70°F/18° to 21°C is ideal, although a range of 50°F/10°C at night to as warm as 85°F/29°C in the day will give acceptable results. When seedlings are 2 in. tall, transplant each into a 3- or 4-in. pot; keep seedlings in sunny area until they reach planting size. When buying tomato plants, look for compact ones with sturdy stems; avoid those that are tall for the pot or have flowers or fruit.

Plant in a sunny site in well-drained soil. Tomato plants prefer neutral to slightly acid soil; add lime to very acid soil or sulfur to alkaline soil the autumn before setting out plants. Space plants 1 1/2–3 ft. apart (staked or trained) to 3–4 ft. apart (untrained).

Make planting holes extra deep and set in seedlings so lowest leaves are just above soil level. Additional roots will form on buried stem and provide a stronger root system.

If you live in an area where summers are cool or short, or if you want to get an early start, take steps to speed growth and protect tomatoes from frost. A combination of plastic mulch and floating row covers is probably most effective. Individual plants can be protected with paper or plastic caps known as hot caps (some have water-filled cylinders that trap heat effectively to provide maximum protection).

Tomato management and harvest will be most satisfying if you train plants to keep them off the ground as much as possible. Untrained plants will sprawl, and some fruit will lie on soil, where it often suffers from rot, pest damage, and discoloration. For training indeterminate varieties, the usual practice is to drive a 6-ft.-long stake (at least 1 by 1 in.) into ground a foot from each plant. Use soft ties to hold the plant to the stake as it grows. Slightly easier in the long run—but more work at planting time—is to grow each plant in a wire cylinder made of concrete reinforcing screen (6-in. mesh). The screen is 7 ft. wide, which is just right for cylinder height. Put stakes at opposite sides of cylinder and tie cylinder firmly to them. As the vine grows, poke protruding branches back inside the cylinder.

Tomato plants need regular moisture at root level; they are deep rooted, so water heavily each time you water. If soil is fairly rich you won’t need to fertilize at all. In ordinary soils, feed lightly every 2 weeks from the time first blossoms set until the end of harvest; or give a single application of controlled-release fertilizer when planting.

Whiteflies are common pests of tomato plants. Large green caterpillars with diagonal white stripes that feed upside down on leaf undersides are hornworms; handpick them. In Hawaii, wrap developing fruit clusters in paper or cloth bags to protect from melon flies. Tomatoes are subject to a long list of diseases, some common only in certain regions. Your Cooperative Extension Office is the best source of control measures for most tomato diseases. If plants are growing strongly, then suddenly wilt and die, they may have been sabotaged by gophers. If you can find no evidence of these rodents, plants probably are suffering from verticillium wilt, fusarium wilt, or both; pull them out and discard them. Diseases live over in soil, so plant in a different location every year and try varieties resistant to wilt or certain other diseases (see introduction to Tomato varieties, below).

In the Pacific Northwest, lessen chance of late blight (which spots leaves and stems, rots fruit) by avoiding overhead sprinkling. Blight declines as weather warms; destroy plant debris after harvest.

Some tomato problems—leaf roll, blossom-end rot, cracked fruit—are physiological and can usually be corrected (or prevented) by maintaining uniform soil moisture. Mulching will help conserve moisture in very hot or dry climates.

If you have done everything right and your tomatoes fail to set fruit in the spring, use hormone spray on blossoms. Tomatoes often fail to set fruit when night temperatures drop below 55°F/13°C. In chilly-night areas, select cold-tolerant varieties (especially small-fruited strains). Fruit-setting hormone often speeds up bearing in the earlier part of the season. Tomatoes can also fail to set fruit when temperatures rise above 100°F/38°C, but hormones are not effective under those conditions.

Harvest fruit when it is fully colored up and juicy; keep ripe fruit picked to extend season. When frost is predicted, harvest all fruit, both green and partly ripe. Store in a dry place away from direct sunlight at 60° to 70°F/16° to 21°C; check often for ripening.

Following are types of tomatoes you can buy as seeds or started plants. The number of varieties is enormous and increases every year; there are choices for every taste and every region. It’s wise to consult a knowledgeable nursery, your Cooperative Extension Office, and other gardeners to find out which varieties flourish in your local climate and soil.

If certain diseases or nematodes cause trouble locally, you may be able to grow varieties that resist one or more problems. Keys to resistance you may see on plant labels or in catalog descriptions include V (verticillium wilt), F (fusarium wilt), FF (Race 1 and Race 2 fusarium), T (tobacco mosaic virus), N (nematodes), A (alternaria leaf spot), and L (septoria leaf spot). For example, a variety labeled VFFNT means that it resists verticillium wilt, two races of fusarium wilt, nematodes, and tobacco mosaic virus.

Cool-summer tomatoes. These will ripen fruit where accumulated heat is too low for most tomatoes. Nurseries in cool-summer areas usually offer locally adapted varieties, such as ‘San Francisco Fog’, ‘Oregon Pride’, and ‘Seattle Best of All’. Many early varieties, especially ‘Early Girl’ and ‘Stupice’, also do well where summers are cool.

Early tomatoes. These tomatoes set fruit at lower night temperatures than other tomatoes do; ‘Early Girl’, ‘Burpee’s Early Pick’, and ‘Quick Pick’ are standards. Very short-season regions in the far north and high-elevation areas, have their own very early varieties, which set fruit at surprisingly low temperatures; ‘Early Tanana’ and ‘Subarctic Maxi’ are examples.

Hawaiian tomatoes. Varieties developed especially for Hawaii resist nematodes and common diseases found there. They include ‘N-5’, ‘N-52’, ‘N-65’, ‘N-69’, ‘Anahu’, ‘Healani’, ‘Kalohi’, and ‘Puunui’.

Heirloom tomatoes. Varying in size, appearance, and plant habit, these represent old varieties that have been maintained by enthusiasts in different parts of the country. Most are grown for excellent flavor. ‘Brandywine’ and ‘Cherokee Purple’ are among the many popular heirloom varieties.

Hybrid tomatoes. Some suppliers tout certain tomatoes as hybrids. They are usually referring to first generation offspring of controlled parent lines, sometimes indicated by F1 after the name. These varieties are more predictable and uniform in growth and fruit quality. Some are giants like ‘Beefmaster’ and ‘Big Beef’, but hybrid paste tomatoes are also available.

Large-fruited tomatoes. These grow to full size in areas where both days and nights are warm. Fruits can weigh a pound or even more. ‘Beefsteak’, ‘Beefmaster’, and ‘Big Beef ’ are typical. ‘Burpee’s Supersteak Hybrid’ can produce 2-lb. fruits; ‘Delicious’ has borne a 7 3/4-lb. tomato.

Main crop or standard tomatoes. ‘Celebrity’, ‘Big Boy’, and ‘Better Boy’ are widely grown. ‘Heatwave’ is popular in extremely hot climates. ‘Ace’ and ‘Pearson’ are local favorites in California.

Novelty tomatoes. Among these are yellow and orange varieties such as ‘Orange Queen’, ‘Mountain Gold’, ‘Husky Gold’, and ‘Lemon Boy’. ‘Caro Rich’ is very high in vitamin A and beta carotene. There are also tomatoes that are deep reddish brown (‘Black Prince’), white (‘New Snowball’, ‘White Beauty’), tomatoes with striped fruit (‘Green Zebra’, ‘Tigerella’), and even one with fruit that is green when fully ripe (‘Evergreen’). ‘Long Keeper’ will stay fresh in storage for 3 months. ‘Stuffer’ and ‘Yellow Stuffer’ yield large, nearly hollow fruits that resemble bell peppers.

Paste tomatoes. Bears huge crops of small, oval, thick-meated fruits with small seed cavities. Sometimes called plum tomatoes. Favorites for canning, sauces, and tomato paste; also good for drying. ‘Roma’, ’San Marzano’, ‘Viva Italia’, and yellow ‘Italian Gold’ are examples.

Small-fruited tomatoes. Bear fruits ranging from very tiny (currant size) to the size of large marbles. Shapes and colors are indicated by names: ‘Red Cherry’, ‘Red Pear’, ‘Yellow Cherry’, ‘Yellow Pear’. Those with very small fruits include ‘Gardener’s Delight’, ‘Sun Gold’, ‘Supersweet 100’, ‘Sweet 100’, and ‘Sweet Million’.

Grape tomatoes, such as ‘Juliet’, produce large grape-like clusters of smallish fruit. Small-fruiting types that grow on small plants suitable for containers or hanging baskets include ‘Tiny Tim’, ‘Small Fry’, and ‘Patio’.