Tomato (Lycopersicon esculentum)-Hort Answers - University of Illinois Extension
University of Illinois Extension

University of Illinois Extension

Hort Answers

Vegetable

Tomato
Lycopersicon esculentum


 
Culture

Apply starter fertilizer when transplanting. Hoe or cultivate shallowly to keep down weeds without damaging roots. Mulching is recommended, especially for gardeners who wish to maintain their plants for full season harvest. Black plastic or organic materials are suitable for mulching. Delay application of organic materials until after the soil has warmed completely in early summer so that growth is not retarded by cool soil temperatures early in the season. Water the plants thoroughly and regularly during prolonged dry periods. Plants confined in containers may need daily or even more frequent watering. Side-dress nitrogen fertilizer (ammonium nitrate) at the rate of one pound per 100 feet of row (equivalent to 1 tablespoon per plant) after the first tomatoes have grown to the size of golf balls. If ammonium nitrate is not available, use 3 pounds of 10-10-10 fertilizer. Make two more applications 3 and 6 weeks later. If the weather is dry following these applications, water the plants thoroughly. Do not get fertilizer on the leaves.

Many gardeners train their tomato plants to stakes, trellises or cages with great success. Not all varieties, however, are equally suitable for staking and pruning. Tomato cages may be made from concrete-reinforcing wire, woven-wire stock fencing or various wooden designs. Choose wire or wooden designs that have holes large enough to allow fruit to be picked and removed without bruising. The short, small, narrow type often sold at garden centers is all but useless for anything but the smallest of the dwarf types. Most modern determinate tomatoes easily grow 3 to 4 feet tall and indeterminates continue to get taller until frozen in the fall, easily reaching at least 6 feet in height. Use cages that match in height the variety to be caged and firmly anchor them to the ground with stakes or steel posts to keep the fruit-laden plants from uprooting themselves in late summer windstorms.

Trellis-weave systems have recently been developed for commercial operations and can work just as well in a garden planting. Tall stakes are securely driven into the tomato row about every two or three plants in the row. Make sure the stakes are tall enough to accommodate the growth of your tomato varieties and make sure they are driven very securely into the ground to prevent wind damage. (The woven rows of tomatoes can catch much wind.) As the tomatoes grow upward, strings are attached to the end posts and woven back and forth between the supports, holding the tops of the plants up and off the ground. This operation is repeated about as often as the tomatoes grow anothersix inches, until the plants reach maturity. The fruit is held off the ground as with staked or caged plants; but the foliage cover is better than with staked plants, and the fruit is more accessible than with cages.

 
 
Cultivars

Hundreds of varieties of tomatoes are now available for the home gardener. They range widely in size, shape, color, plant type, disease resistance and season of maturity. Catalogs, garden centers and greenhouses offer a large selection of tomato varieties and choosing the best one or two varieties can be extremely difficult. Evaluate your needs, then choose the varieties best suited to your intended use and method of culture.

Tomato plants fall into one of two types that affect ultimate plant height and cultural requirements. Tomatoes are determinate if they eventually form a flower cluster at the terminal growing point, causing the plant to stop growing in height. Plants that never set terminal flower clusters, but only lateral ones and continue indefinitely to grow taller are called indeterminate. Older varieties are almost all indeterminate. These can be counted upon to produce abundant foliage and to ripen flavorful fruit. They may, however be extremely late in maturing. The first determinate varieties developed had real problems with inadequate foliage cover and taste, but they ripened very early. Newer determinates produce better foliage, may grow taller and ripen fruit of similar quality to modern indeterminate varieties. They still tend to ripen their fruit over a shorter period of time, so successive plantings may be desirable with determinates to keep the harvest coming through the entire season. Determinate vines are easier to control and support during the growing season. Some of the extreme dwarf types are determinate as well as dwarf, producing some truly tiny mature plants. Guide to AbbreviationsA=AlternariaF=Fusarium N=nematodes T=Tobacco mosaic virusV=VerticilliumOP=Open Pollinated AAS=All America Selection

  • First-Early Red (60 or fewer days to harvest): These varieties have more compact plant growth than the main-season varieties and sunburning of the fruit is a problem in hot weather. The main crop varieties are generally far superior for summer long harvest. First early varieties are better suited for northern areas, where the growing seasons are shorter and the summers cooler. They have small to medium-sized red fruit and are usually not suitable for pruning. Examples: Sub Arctic Plenty (45 days to harvest; 3 to 4 ounces; fruit concentrated in center clusters; determinate), Early Cascade (55 days; 4 ounces; trailing plant, large fruit clusters; indeterminate; resistant to VF), Early Girl (54 days; 5 ounces; earliest full size; indeterminate; resistant to V), and Quick Pick (60 days; 4 ounces; round, smooth, heavy yield; indeterminate; resistant to VFNTA).
  • Medium-Early Red (60 to 69 days): These varieties are intermediate between the extreme earliness of the first earliest and the sounder plant type and production characteristics of the main crop types. Fruit size is improved, as is quality. The real tomato harvest season begins with the medium early varieties. Champion (65 days to harvest; 10 ounces; solid, smooth, large; indeterminate; resistant to VFNT) Mountain Spring (65 days; 9 ounces; globe, very smooth; determinate; resistant to VF)
  • Main-Crop Red: Most of the main crop varieties bear medium sized to large fruit, have adequate foliage cover, and are relatively free from fruit cracking and other deformities. They are suitable for growing on mulch, in wire cages or on trellises. Many of them can be pruned and trained to stakes. As the name implies, they should make up the bulk of the main crop harvest because they have superior yield, better staying power in the garden and fruit of high quality. Examples: Celebrity (70 days to harvest; 10 ounces; large, productive; determinate; resistant to VFFNT), Mountain Delight (70 days; 10 ounces; no green shoulders; determinate; resistant to VF), Fantastic (70 days; 9 ounces; deep globe, high yield; indeterminate), Better Boy (72 days; 12 ounces; easy-to-find plants; indeterminate; resistant to VFN), Mountain Pride (74 days; 10 ounces; smooth, flat globe; determinate; resistant to VF), Floramerica (75 days; 12 ounces; All America Selection winner, bright red; determinate; resistant to VF), Burpee's Big Girl (78 days; 16 ounces; crack-resistant, attractive fruit; indeterminate; resistant to VF), andSupersonic (79 days; 12 ounces; solid, crack resistant; indeterminate; resistant to VF).
  • Extra-Large Red: These varieties are relatively late maturing. The fruits may be extremely large but also can be misshapen, with rough scar tissue ("cat-facing") on the blossom end. When this scar tissue must be cut away, some of the advantage of extra-large size is lost. Large size, though, is almost never about total yield, but more often about the novelty of huge size. Some of the newer hybrid large types like Supersteak and Beefmaster have fruit with much more consistent shape. Examples: Delicious (OP) (77 days to harvest; over 1 lb.; world record (7 lb. 12 oz) with this variety; indeterminate), Supersteak (80 days; 1 to 2 lb.; extra meaty; indeterminate; resistant to VFN), Beefmaster (81 days; 1 to 2 lb.; large Beefsteak type; indeterminate; reistant to VFN).
  • Yellow or Orange: Contrary to popular belief, yellow and orange fruited varieties are not significantly lower in acid content than red tomatoes, and they are equally safe to can or process. They "taste" sweeter than red varieties, because they have a higher sugar content. Current varieties in this classification have much earlier maturity and better plant growth characteristics than older yellows and oranges, which tended to be big, sprawling and late maturing. Examples: Mountain Gold (OP) (70 days to harvest; 8 ounces; deep tangerine orange; determinate; resistant to VF), Lemon Boy (72 days; 7 ounces; lemon yellow, mild flavor, productive; indeterminate; resistant to VFN), Jubilee (OP) (72 days; 8 ounces; deep orange-yellow; indeterminate), andGolden Boy (80 days; 8 ounces; deep golden fruit, few seeds; indeterminate).
  • Pink: These varieties always have maintained a loyal following in certain regions of the country. Pinks traditionally have been similar to yellows with regard to plant type and maturity. Recent breeding work has developed disease-resistant plants with very attractive fruit. For the highest eating quality, some of the older types may still be at the top for flavor. Examples: Pink Girl (76 days to harvest; 7 ounces; smooth, crack resistant; indeterminate; resistant to VF), and Brandywine (OP) (80 days; 12 ounces; large, rough, heirloom; juicy, great taste; indeterminate).
  • Other Colors and Types: Although odd colors and types have been around for a long time, they have experienced a resurgence of popularity, fueled in part by the upscale salad bar. As these outlets have competed to offer the newest and brightest assortment of produce, some almost-forgotten tomatoes have been "rediscovered." Examples: White Wonder (OP) (85 days to harvest; 8 ounces; creamy white flesh and skin; indeterminate), Evergreen (OP) (85 days; 8 ounces; green skin tinged with yellow; flesh bright green at maturity; indeterminate), Long Keeper (OP) (78 days; 6 ounces; orange skin, orange-red flesh; solid, keeps for weeks; indeterminate), andYellow Stuffer (OP) (80 days; 4 ounces; lobed, lemon yellow, shaped like pepper; semi-hollow, easy to stuff; indeterminate).
  • Red Paste Types: Paste tomatoes are usually used for making catsup, paste and sauces and for canning whole. Their solid, meaty, low-moisture flesh makes processing these products less complicated. Recently, some of them are becoming trendy and popular for eating fresh. These are usually short plant types that tend to set up a large load of fruit in a short time and then ripen a large proportion of this fruit at once. With tomatoes used fresh, it is usually seen as an advantage to have fruit ripening over an extended season on individual plants, but ripening most of the crop in a short period has been a bonus for paste tomatoes because processing activities are best done in fairly large lots. Examples: Veeroma (OP) (72 days to harvest; 2 to 3 ounces; early Roma type, deep square shape; det; resistant to VF), Roma (OP) (75 days; 2 ounces; standard red plum, tolerant to early blight; determinate; resistant to VF), Sam Marzano (OP) (80 days; 3 ounces; deep red, crack resistant, meaty and dry; determinate), andViva Italia (80 days; 3 ounces; meaty, sweet; good fresh; determinate; resistant to VFN).
  • Small-Fruited/Salad: These varieties are generally vigorous growing and productive. They vary in size from 1 to 1-1/2 inches in diameter and are usually suitable for pruning. Production per plant is very high, to the point that picking may become tedious. Whole clusters may sometimes be picked at one time to speed the harvest. Splitting seems to be more of a problem with cherries, though newer hybrids have attempted to lessen the problem. These types are usually described as especially sweet and tasty. Examples: Super Sweet 100 (70 days to harvest; 1 inch; red, cherry-sized fruit in large clusters; indeterminate; resistant to VF), Sweet Million (65 days; 1 inch; red, sweet, crack resistant; large clusters; indeterminate; resistant to FNT), Yellow Pear (OP) (70 days; 1 inch; clusters of yellow, pear-shaped fruit; indeterminate), Large Red Cherry (OP) (70 days; 1-1/2 inch; solid, deep red, tasty fruit; indeterminate), andMountain Belle (65 days; 1 1/4 inch; red, crack resistant, ripens uniformly and holds on the vine; determinate; resistant to VF).
  • Dwarf/Container: These tomatoes are popular for use in containers, hanging baskets and garden or patio locations where space is limited. Because more people now live where traditional vegetable gardening is not possible, container and patio gardens have become more popular. Their ornamental value is an added benefit and their fruit quality has recently been improved as well. They have fruit in red and some other colors and are not suitable for pruning (except the new Husky hybrids). Examples: Tiny Tim (45 days to harvest; 1 inch; very dwarf, red cherry fruit; determinate), Cherry Gold (45 days; 1 inch; golden version of Tiny Tim; determinate), Red Robin (55 days; 1 inch; super-dwarf plant, 6 inches tall; mild taste; determinate), Yellow Canary (55 days; 1 inch; similar to Red Robin, but yellow fruit; determinate), Pixie Hybrid II (52 days; 2 ounces; compact dwarf plants; determinate), Patio Hybrid (65 days; 3 ounces; strong dwarf plants, relatively large fruit, ideal container plant; determinate), Small Fry (72 days; 1 inch; red, good in hanging baskets; determinate), Husky Red Hybrid (68 days; 6 ounces; dwarf plant, large fruit; extended harvest; indeterminate; resistant to VF), Husky Gold Hybrid (70 days; 6 ounces; AAS winner; same plant types as Red and Pink; gold fruit; indeterminate; resistant to VF), and Husky Pink Hybrid (72 days; 6 ounces; smooth pink fruit on same husky-type plant; indeterminate; resistant to VF).

Greenhouse Gardeners interested in growing greenhouse tomatoes should know that specific varieties have been developed for this environment. Some catalogs now routinely list these types, which should be used for the most satisfactory results. Consult catalogs for varieties available. Heirloom A particularly large number of heirloom tomato varieties are available today, mainly because tomatoes normally do not cross-pollinate. Seed saved from fruits of non-hybrid varieties produce plants fairly identical to the parent plant. Many of the odder colors and types that have resurfaced lately have their origins in these older, self-saved varieties. The plant type is usually large, sprawling and late compared to current commercial varieties. Disease resistance may also be suspect. If, however, the gardener wants to try a few truly weird or tasty types, these usually mature some fruits almost anywhere except in the shortest-season areas. Specialty seed houses and exchanges are a source of the widest variety of heirloom tomatoes imaginable.

 
 
Planting Time
Buying transplants or starting seeds indoor early, gets tomatoes off to the best start in the garden when warm weather finally arrives and it saves several weeks in growing time. Some gardeners transplant their tomatoes soon after the soil is prepared for spring gardening, when there is a high risk of damage from freezing. Be prepared to cover early set plants overnight to protect them from frost. For best results with very early plantings, consider black plastic mulch and floating row covers for heat accumulation and frost protection. For best results with minimal risk, plant when the soil is warm, soon after the frost-free date for your area.

 

 
Harvest Time
Tomatoes should be firm and fully colored. They are of highest quality when they ripen on healthy vines and daily summer temperatures average about 75°F. When temperatures are high (air temperature of 90°F or more), the softening process is accelerated and color development is retarded, reducing quality. For this reason, during hot summer weather, pick your tomatoes every day or two, harvest the fruits when color has started to develop and ripen them further indoors (at 70 to 75°F). On the day before a killing freeze is expected, harvest all green mature fruit that is desired for later use in the fall. Wrap the tomatoes individually in paper and store at 60 to 65°F. They continue to ripen slowly over the next several weeks. Whole plants may be uprooted and hung in sheltered locations, where fruit continues to ripen.

 

 
Spacing
The space required depends upon the growth pattern of the variety and method of culture. Space dwarf plants 12 inches apart in the row, staked plants 15 to 24 inches apart and trellised or ground bed plants 24 to 36 inches apart. Some particularly vigorous indeterminate varieties may need 4 feet between plants and 5 to 6 feet between rows to allow comfortable harvest room.

 

 
Soil Conditions
Moist, Well-Drained
 
 
Exposure/Light Requirements
Full Sun
 
 
Uses
Canning
Fresh
 
 
Pests and Problems

Bacterial Disease

Environmental Damage

Fungal Disease

Herbicide Injury

Insect Damage


Additional pests and problems that may affect this plant:

Insect pests:

  • Tomato hornworm
  • Leaf miner
  • Mites
  • Stinkbug

Diseases:

  • Fusarium wilt (Fusarium oxysporum f. sp. lycopersici)
  • Gray mold (Botrytis cinerea)
  • Powdery mildew (Leveillula taurica)
  • Sclerotinia stem rot (Sclerotinia sclerotiorum)
  • Southern blight (Sclerotium rolfsii)
  • Nematode Diseases: Root knot nematode (Meloidogyne spp.)
  • Virus Diseases: Tobacco mosaic, Cucumber mosaic, Tobacco etch, Spotted wilt
  • Abiotic Diseases: Blossom end rot, Fruit cracking, Lightining injury,Sunscald
 
Additional Notes
Tomato is, today, the most popular garden vegetable in America. For many years, however, tomatoes (then called "love apples") were considered poisonous and were grown solely for their ornamental value. Tomatoes are usually easy to grow and a few plants provide an adequate harvest for most families. The quality of fruit picked in the garden when fully ripe far surpasses anything available on the market, even in season. The tomato plant is a tender, warm-season perennial that is grown as an annual in summer gardens all over the continental United States. Spring and fall freezes limit the outdoor growing season.

 

 
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