How to Grow Delicious Tomatoes
All you need to know to successfully
harvest one of the most commonly grown and most loved vegetables.
The tomato originated in the Andean Mountains
of South America, but the Inca people living in the area did not cultivate
it. It traveled over 2,000 miles north of its center of origin to Central
America where the pre-Mayan people first domesticated tomato plants. The
Aztecs were the first people to cultivate, eat and name the tomato –
tomatl or xtomatl. It was the wild, cherry size tomato,
Lycopersicon esculentum var cerasiforme, from which modern tomatoes are
The earliest written records of the tomato are
in herbal books. Botanists placed the tomato in the nightshade family, which
includes many poisonous plants. People thought tomatoes were poisonous also,
and one herbal said, “This plant is more pleasant to the sight than either
to the taste or smell because the fruit being eaten provoketh loathing and
vomiting.” As a result, tomatoes were not eaten in England during the 1500s and 1600s.
It wasn’t until the 1830s that people in North
America began to relish tomatoes as food. Colonel Robert Gibbon Johnson is
credited for an event that changed opinions about tomatoes. In Salem, New
Jersey in 1820 Colonel Johnson staged an event to eat a basketful of
tomatoes at the local courthouse. An audience gathered to watch him die. His
physician warned that he would, “foam and froth at the mouth...double over
with appendicitis....if wolf peach is too ripe and warmed by the
sun....exposing himself to brain fever.” Colonel Johnson survived and slowly
people began to accept the tomato as food.
In 1835 tomatoes were regularly available in
local markets in North America. The most popular uses were in preserves,
pickles and catsup. Many cookbooks of the era highly recommended cooking
tomatoes for at least three hours so that the “raw taste” would be lost.
|It wasn’t until the 1830s that
people in North America began to relish tomatoes as food.
The botanical name for tomato has changed
several times. Its earliest name was Lycopersicon or literally,
wolf peach. Once the tomato was placed in the Solanum (Solanaceae)
family, the botanical name changed to Solanum lycopersicon. Today
the tomato is known as Lycopersicon esculentum, literally edible
There are three ways to classify tomatoes. They are fruit shape,
earliness to mature, and color. Tomatoes are quite diverse and many
gardeners enjoy growing several types. There are five major fruit shapes.
From the smallest to the largest, they are cherry, plum, pear, standard, and
beefsteak. There are numerous cherry varieties available to gardeners. They
are defined by weight in the range of 1/4 to one ounce. Cherry tomatoes are
produced in clusters like grapes but have a tendency to crack if not picked
regularly. The plum and pear tomatoes are the fruit shapes as described and
weigh between two to six ounces. Normally they have meaty interiors, thick
fruit walls and less gel than others. The standard tomatoes are round to
globe shape weighing four to eight ounces. The beefsteak size can be two
pounds or more depending upon variety. The shape is usually oblate.
Tomatoes are categorized by their maturity date. The number of days to
maturity means the number of days from planting outdoors to expected ripe
fruit. Tomatoes can be early, mid-season or late. Early tomatoes will ripen
from 55 to 65 days from transplanting. Mid-season is considered 66 to 80
days for ripe fruit. Late types require over 80 days to ripen.
are colorful, ranging from creamy white through lime green to pink, yellow,
golden, orange and red. The major differences among the colors are the
flavors. Pink, yellow and orange are milder tasting than most red varieties.
We have been led to believe that the yellow or orange tomatoes have less
acid content but this is not necessarily true. People taste less acid in
There are basically two types of plant growth for
tomatoes. They are determinate and indeterminate. You can select the habit
that is best for your garden use. Indeterminate growth means varieties grow,
blossom. and produce tomatoes throughout the growing season until killed
possibly by frost. The continuous growth produces many main stems all
capable of flowering and producing fruit. Because of the abundant lush
growth, pruning indeterminate plants is highly recommended. To support the
plant growth and to keep tomatoes off garden soil, the National Garden
Bureau recommends a stake for tomato plant support. Plants can be easily
trained to the stake for vertical growth.
The best combination of pruning
and staking is to remove all but two growing stems and loosely tie the stems
to the stake. To identify an indeterminate plant, look at the main stem.
This can be identified by the growing tip at the top or end of the stem. In
a normal plant, there are three leaf stems growing from the main stem. Above
or below the three stems you will find a flower cluster. This pattern is
repeated over and over on the main stem.
Indeterminate plants may be
pruned to harvest larger tomatoes. Without pruning, plants produce smaller
tomatoes but more of them. To prune, pinch out suckers. These are shoots
that develop in the “U” between the main stem and a branch. Pinch out these
shoots. This is best done by hand, pinching the shoots between fingers.
Determinate tomato plants are relatively compact and produce a full bushy
plant. These plants will reach a predetermined height or number of fruit
clusters and not grow beyond it. The plants flower, set fruit and ripen in a
short time so that the main harvest is concentrated into a few weeks. This
may be ideal for gardeners who wish to can or preserve the fresh tomato
harvest. Instead of three leaf stems and a flower cluster, determinate
varieties have two leaf stems and a cluster.
There is a third type called
semi-determinate which is a bushy plant but will set and ripen fruit over a
longer period of time than a normal determinate. The best way to grow
determinate or semi-determinate plants is to not prune and place a cage
around the tomato while still quite small. The plant grows filling the cage.
Gardeners need only pluck ripe fruit.
Many gardeners start their tomato plants from seed.
Tomato seed should be sown indoors 6 to 12 weeks before the last expected
frost date. Most seed will germinate in 5 to 12 days. For maximum
germination, the soil temperature needs to be warm, about 70 to 75 degrees
F. Use a prepared, sterile germination mix as the growing media. Place this
media in containers with holes for drainage. Water the media thoroughly and
allow to drain. Sow seeds on the media and cover lightly with media or
vermiculite. Mist the top of the media and cover with newspaper or plastic
to prevent the media from drying out. Keep in a warm place and check every
day for germination.
When seeds have sprouted, remove the cover. Place in
a sunny location, keep seedlings warm and water regularly. After a week or
two transplant young plants into small 2 inch individual peat pots filled
with a sterile soilless growing media. Dig out plants, carefully separate
and disturb the roots as little as possible. Make hole in media, place plant
into hole and push media next to plant to hold it upright. The plant can be
planted deeply, to the first leaf stem. Roots will develop along the buried
main stem. Provide as much direct sunlight as possible. Up to 12 hours of
light is desirable at this stage. Gardeners can use grow lights to
supplement the natural sunlight. The plants may stretch or get leggy if they
do not receive enough direct sunlight.
Preparing to Plant
Digging soil to add air pockets to the structure is
advised for heavy clay soil. Do a soil analysis to learn if any important
nutrients are missing. Add compost and other organic materials to your soil
to improve nutrients, texture and moisture holding capacity. Break large
clods of soil into small pieces. Rake the garden bed so that it is flat and
It is recommended to harden off plants before placing
them in the garden. The young plants are tender and need to be exposed
gradually to the harsh outdoor climate. Put plants outside in a protected
area where they will receive full sun, but are out of the wind. Move plants
inside at night. Continue this for three to four days. The day and night
temperatures should be increasing but if it drops to 50 degrees F, take them
inside. After four days allow plants to be outside all day and night. After
being outside for a week or two, the plants should be hardened off and ready
Tomatoes are one of the easiest garden plants to
grow. They need as much direct sunlight as possible to produce the highest
yield. Wait until the air and soil have warmed before transplanting. Native
to the tropics, tomatoes require warm, 70 degrees F, temperatures for good
There are several ways to plant a tomato. The
traditional method is to dig a hole in the soil and place the plant in it.
For northern gardeners, if your plants are tall and leggy, don’t worry, just
dig a deeper hole and bury the plant to the first leaf stem. The buried stem
will grow roots and this helps develop a deep root system. This deep hole
planting is not recommended for southern gardeners due to fungal rot
attacking young stems.
Some people use the trench method of planting. A long
shallow hole is dug and the tomato plant laid horizontally into the trench.
Pinch leaves off of the stem. Allow the top two to three inches of stem to
lead out of the trench. Push soil on top of the trench and push a pillow of
soil under the top stem. The stem will grow up towards the sun. Because the
bulk of the stem is buried at a shallow level, the newly developing roots
and surrounding soil will warm up relatively quickly. This is a boon to
gardeners living in a short growing season. With the roots close to the
surface, be sure to water deeply to encourage deep root growth.
After planting, water. Continue watering lightly each
day if it does not rain. After about two weeks of regular watering, plants
should be established and you can decrease the watering. Throughout the
growing season water weekly if it does not rain. Established tomato plants
need about one inch of precipitation per week from rain or irrigation.
A cloche or hot cap can be used to protect the newly
transplanted tomatoes from freezing if night temperatures drop. Tomato
plants will probably die if exposed to 32 degrees F without protection as
they are not frost tolerant.
|Gardeners living in urban
environments can grow tomatoes in tubs or large patio containers.
Tomatoes need phosphorus, nitrogen, potash, and minor
elements. Many gardeners add a fertilizer or rich compost to the soil. The
easiest commercial fertilizer to use is a time release fertilizer at the
time of planting. Do not over fertilize because then you will have lush,
tropical plants with little fruit set. Be sure to select a fertilizer that
contains more phosphorus (P) than nitrogen(N) or potassium (K). Phosphorus
promotes flowering and fruit set.
Gardeners living in urban environments can grow
tomatoes in tubs or large patio containers. For best results select a
determinate or compact bush plant habit for container culture. Cherry
tomatoes can be grown in containers too. The container needs to be deep, at
least a foot, with drainage holes on the bottom. Use a sterile growing
media. Keep the plants evenly watered without overwatering. Allow the plants
to receive as much direct sunlight as possible. Low light levels result in a
leggy plant. They will still produce fruit, just fewer of them. Feed plants
using a water soluble fertilizer. Water often during hot weather.
To achieve the full tomato flavor, allow the fruit to
fully ripen on the plant. To harvest, gently hold the tomato and twist so
that the stem separates from the vine. It is easy to damage the plant by
pulling the entire fruit cluster off of the plant. Take the fruit one at a
time unless you wish to remove the entire ripe cluster. Tomatoes are best
stored at room temperature. At the end of the season when frost is
predicted, all green tomatoes can be harvested and placed on a windowsill.
Most will gradually turn red and have some degree of tomato flavor. Placing
unripe tomatoes in a closed paper bag will hasten the ripening process.
Most gardeners successfully grow tomatoes in their
gardens without significant problems. The best approach is to be observant.
Look at leaves regularly and notice any difference in leaf color, size or
shape. Holes in leaves usually indicate there are insects eating leaves. It
is best to rotate tomatoes and other crops in your garden. Do not grow the
same crop in the same place year after year.
When browsing through the tomato section of seed
packets in a store you may notice the letters V, F, N or TMV on the packet
or in the description. These letters mean the plant is genetically tolerant
of the following diseases or virus.
Verticillium Wilt (V) is caused by a soilborne
fungus. The symptoms of infection are wilting of older leaf tips, yellowing
and browning of leaves in a V-shaped pattern and leaf drop beginning with
the older foliage. As the fungus moves throughout the plant, all leaves curl
upward and the stunted plant will not respond to water or fertilizer. Cool
weather conditions encourage this disease which is common in soil.
Fusarium Wilt (F) is also a soilborne fungal disease.
This infection commonly occurs when the soil is above 75 degrees F. Light
sandy soils are most susceptible to Fusarium, also soils with low Ph.
Symptoms of this disease are yellowing, curving and dying leaves. Infected
plants are stunted and fruits will be small or deformed.
|To offer the best, most nutritious
food, grow your own tomatoes and eat them fresh from your garden.
Nematodes (N) are microscopic worms living in the
soil. Some nematodes are good, some bad. The bad ones are root knot
nematodes and cause plants to wilt or portions of plants to dieback. To
identify this problem, pull the tomato with roots from the soil. The roots
will have growths or galls on them. This means the root knot nematodes are
Tobacco Mosaic Virus (TMV) is one of the most
widespread viruses affecting tomatoes. Weeds harbor the virus and insects
feed on the weeds transmitting the virus to the plant. The virus source is
tobacco. This virus turns leaves dark or light green, possibly even a
mottled yellow appearance. It can also be caused by people who smoke
cigarettes handling plants.
There is no cure for these four problems. If you
suspect any of these problems may be infecting your plants, they should be
destroyed. Do not place diseased plants into your compost. The easiest way
to insure you do not have problems with these diseases is to grow tomatoes
with disease or virus tolerances.
There are three fruit disorders that gardeners may
encounter. They are blossom-end rot, cracking or catfacing, and sunscald.
One of the most common fruit disorders is blossom-end rot. It begins with
tan lesions on the blossom end of the tomato. The lesions enlarge and become
dark sunken areas. It begins when fruit are about half developed. This rot
appears during periods of high growth or when soil moisture is alternately
high or low. Any soil condition that affects the plant’s uptake of calcium
can result in the rot. To help control this rot, try adding calcium soil
amendments, water during dry weather and use a mulch to maintain more
uniform soil moisture.
Cracking usually occurs near the fruit stem while
catfacing occurs near the blossom end. These are caused by environmental
conditions such as fast growth caused by high temperatures and moisture
levels, initial fruit growth during a dry spell followed by heavy rain or
watering, or excessive swings in day and night temperatures. Some varieties
are resistant to cracking and catfacing.
Lastly, sunscald is the sun burning the tomato skin.
It develops white, shiny, blisters on areas which are exposed to the sun.
Normally, leaf cover keeps the tomatoes in the shade. Sunscald can occur due
to excessive pruning, insect damage to leaves, or foliage disease causing
leaf loss. There are no cures for these fruit disorders once they have
damaged your tomatoes.
Tomatoes will provide your diet with abundant
vitamins and minerals. A fresh, raw tomato contains an exceptional amount of
Vitamin A. In addition, Vitamin C, potassium, and calcium are available. A
raw tomato contains a trace of sodium, whereas regular pack, canned tomatoes
contain 100 times the amount of sodium.
Americans and Canadians consume most of their
lycopene from tomatoes and strawberries. Lycopene contributes to preventing
certain types of cancers including prostate cancer. To offer the best, most
nutritious food, grow your own tomatoes and eat them fresh from your garden.
This article was prepared with assistance
from the National Garden Bureau.