Tomatoes (Lycopersicon esculentum)
are valuable garden plants in that they require relatively little space
for large production. Each plant, properly cared for, yields 10 to 15
pounds or more of fruit.
Tomatoes are warm-season plants that grow best at
temperatures of 70 to 80 F during the day and 60 to 70 F during the
Tomato plants may be started indoors from seed, or
transplants may be purchased from a reputable garden center. If starting
your own plants, use a light soil mix and give the plants plenty of
light. Tall, spindly transplants are usually caused by low light levels
in the home. Unless you have a sunny, south-facing window, supplemental
light will probably be necessary. The seeds are sown six to eight weeks
before the last frost date in your area. A week before transplanting
time, harden-off indoor-grown plants by exposing them to an increasing
number of hours outdoors each day.
May 1-May 30
March 25-Apr. 10
When you are ready to put homegrown or purchased plants
into the ground, select stocky transplants about 6 to 10 inches tall.
Set tomato transplants in the ground, covering the stems so that only
two or three sets of true leaves are exposed. If transplants become
"leggy," horizontal planting of tomato plants is an effective way to
make plants stronger. Roots will form along the buried portion of the
stem, giving better growth and less chance of plant injury from an
excessively weak stem. Do not remove the containers if they are peat or
paper pots, but open or tear off one side to allow roots to become free.
If non-biodegradable containers are used, knock the plants out of the
pots and loosen the roots somewhat. Press the soil firmly around the
transplants so that a slight depression is formed for holding water.
Pour about 1 pint of starter solution (2 tablespoons of 5-10-10 or
5-10-5 fertilizer per gallon of water) around each plant.
If plants are to be staked or trellised, space them 24
inches apart in rows 3 feet apart. Although it requires more initial
work, staking makes caring for tomatoes easier than letting them sprawl.
Since they are off the ground, fruit rots are reduced, spraying is
easier and may be required less, and harvesting is much less work. Use
wooden stakes 6 feet tall and 1 ˝ or 2 inches wide. Drive them 1 foot
into the soil about 4 to 6 inches from the plant soon after
transplanting. Attach heavy twine or strips of cloth to the stakes every
Prune staked tomatoes to one or two main stems. At the
junction of each leaf and the first main stem a new shoot will develop.
If plants are trained to two stems, remove all other shoots, called
suckers, weekly to maintain these two main stems. Pinch shoots off with
Growing tomatoes in wire cages is a popular method among
gardeners because of its simplicity. Cage-growing allows the tomato
plant to grow in its natural manner but keeps the fruit and leaves off
the ground. Using wire cages requires initial expenditure, but they will
last many years. Be sure to get fencing with at least 6-inch spacing
between the wires so that you can get your hand inside to harvest the
If tomato plants in wire cages are
pruned at all, once is enough. Prune to three or four main stems.
Wire-cage tomatoes develop a heavy foliage cover, reducing sunscald on
fruits. Caged plants are less prone to the spread of disease from plant
handling, since they do not have open wounds and are handled less
frequently than staked plants. However, it helps to space the plants
somewhat further apart (3 feet) to allow good air circulation between
plants. Humidity is higher because of the foliage density, and diseases,
such as late blight, spread rapidly in humid situations.
The varieties of tomato plants available may seem
overwhelming, but they can be summed up by several major types:
Midget, patio or dwarf tomato
varieties have very compact vines and grow well in hanging baskets or
other containers. The tomatoes produced may be, but are not
necessarily, the cherry-type (1-inch diameter or less).
Cherry tomatoes have small fruits
often used in salads. Plants of cherry tomatoes range from dwarf (Tiny
Tim) to 7-footers (Sweet 100).
Compact or determinate tomato
plants grow to a certain size, set fruit and then decline. Most of the
early-ripening tomato varieties are determinate and will not produce
tomatoes throughout a South Carolina summer.
Beefsteak types are large-fruited.
These are usually late to ripen.
Paste tomatoes have small
pear-shaped fruits with very meaty interiors and few seeds. They are a
favorite for canning.
Some tomatoes are orange or yellow.
Sometimes the only way to get these is by growing your own.
Winter storage tomatoes are set out
later in the season than most tomatoes and fruits are harvested
partially ripe. If properly stored, they will stay fresh for 12 weeks
or more. While the flavor does not equal that of summer vine-ripened
tomatoes, many people prefer them to grocery store tomatoes in winter.
The following tomato cultivars are
recommended for South Carolina gardens. Most cultivars are
indeterminate, except for Celebrity and Small Fry.
Better Boy, Better Bush Improved,
Big Beef, Celebrity, Early Girl, Park’s Whopper, Terrific
Cherry Type: Juliet, Small Fry,
Super Sweet 100, Sweet Million
Plum Type: Viva Italia
Always choose varieties with disease
resistance. Fusarium wilt is a common disease that can destroy a whole
tomato crop. Many varieties are resistant to this disease. This is
indicated by the letters VF after the cultivar name. VFN means the
plants are resistant to Verticillium, Fusarium and nematodes; VFNT adds
tobacco mosaic virus to the list.
A soil test is always the best method
for determining the fertilization needs of a crop. Information on soil
testing is available in the fact sheet HGIC 1652,
Soil Testing. The desired soil pH for tomatoes is between 5.8
and 6.5. Tomatoes are heavy feeders. Use a starter solution for
transplants. Sidedress when the first fruits are about the size of
quarters, using 1 ˝ ounces of 33-0-0 fertilizer per 10 feet of row.
Sidedress again two weeks after the first ripe tomato with a balanced
fertilizer such as 5-10-5, and repeat this one month later.
Blossom-end rot can be a serious problem with tomatoes.
The main symptom is a dark-colored dry rot of the blossom ends of the
fruit. It occurs when there are extremes in soil moisture, which cause
calcium deficiency in the fruit. When rain or irrigation follows a dry
spell, the roots cannot take up calcium fast enough to keep up with the
rapid fruit growth. Blossom-end rot also occurs if the delicate feeder
roots are damaged during transplanting or by deep cultivation near the
The following measures will help prevent blossom-end
Test the soil and maintain a pH between 6 and 6.5 and
an adequate calcium level by liming or applying gypsum.
Mulch with 2 to 3 inches of materials such as grass
clippings, pine straw and leaves. Mulching prevents rapid soil drying
and allows roots to take up available calcium efficiently.
Do not overfertilize plants with nitrogen or potash.
Excessive amounts of these nutrients depress the uptake of calcium.
Keep moisture levels fairly uniform by regular
watering and by maintaining a mulch layer around the base of the
plants. Water plants during extended dry periods. Tomatoes need 1 to 1
˝ inches of water per week.
Add organic matter to the soil.
This will help "loosen" clay soils and will improve the water-holding
capacity of sandy soils. In either soil, organic matter will increase
plant uptake of water and calcium.
HARVEST AND STORAGE
It takes 55 to 105 days to maturity depending on the
tomato variety. Pick fruit when it is fully vine-ripened but still firm;
most varieties are dark red. Picked tomatoes should be placed in the
shade. Light isn’t necessary for ripening immature tomatoes. Some green
tomatoes may be picked before the first killing frost and stored in a
cool (55 F), moist (90-percent relative humidity) place. Do not store
green tomatoes in the refrigerator since red color will not develop at
less than 50 F. When necessary, ripen fruits at 70 F. Green tomatoes can
be stored at 50 to 70 F for one to three weeks. Ripe tomatoes should be
stored at 45 to 50 F for four to seven days.
Besides blossom-end rot, the following problems are
Leaf roll: This is a physiological condition caused by
Growth cracks: Tomatoes crack when environmental
conditions (drought followed by heavy rain or watering) encourage
rapid growth during ripening of the fruit.
Sunscald: This occurs when tomatoes are exposed to the
direct rays of the sun during hot weather.
Poor fruit set: This occurs for several reasons, such
as extreme temperatures, dry soil, too much shade and excessive
Tomato blossoms are very sensitive to temperature. At
temperatures of 55 to 60 F, pollination can be severely impaired and
very few fruits will form. Temperatures of 90 to 95 F are also very
unfavorable for pollination.
Catfacing: This is a disorder caused by cold, wet
temperatures during fruit set. The fruit is extremely malformed and
For more information, refer to HGIC
2217, Tomato Diseases, and 2218, Tomato Insects.
Excerpted from Home Vegetable
Gardening, EC 570, 2002.