Solving Tomato Problems
FOR IMMEDIATE RELEASE
May 1, 2009
are the most popular vegetable grown in the United
States, said a University
of Illinois Extension
are probably one of the easiest vegetables to grow, but no vegetable is problem
proof," said Ron Wolford. "Here are some of the common tomato problems you may
encounter during the growing season."
spring temperatures can be a problem for newly planted tomato transplants. To
help get your tomatoes off to a good start, mulch tomato transplants with black
plastic. Soil under plastic is around 10 degrees F warmer than uncovered soil.
The mulch also conserves moisture and protects the tomatoes from diseases
spread by water splashing onto the soil. Try red plastic mulch under tomatoes.
Research has shown increased yields when tomatoes are grown with red plastic
"I get calls
in late July from gardeners who have just-ripening tomatoes with a large black
spot on the blossom end," he said. "They are afraid some terrible disease is
going to wipe out their tomatoes. The problem is blossom-end rot and it is not
a disease. The major cause of this condition is fluctuating levels of soil
moisture during dry spells. So watering your plants consistently with one inch
of water per week will keep this condition at bay. Using mulches will also
occurs in some varieties when there is a lot of rain after a dry spell.
occurs after the rains because the tomato absorbs so much water, causing the
fruit wall to crack," he said. "These cracks are avenues for fungus and
bacteria that can cause rot. Watering tomatoes consistently with one inch of
water per week will alleviate this condition. Tomato varieties resistant to
cracking include Burpee's Big Girl, Supersonic, Pink Girl and Sam Marzano."
blossom drop is very common with high summer temperatures. Tomatoes will drop
blossoms when daytime temperatures in the summer are above 90 degrees F.
Blossoms will also drop earlier in the growing season when night temperatures
drop below 55 degrees F.
really nothing you can do except to wait for cooler temperatures," said Wolford.
common on tomatoes that are exposed to sun on plants that have lost leaves
because of disease or insect problems. The sunburned areas become tan to white,
making the tomato susceptible to disease organisms. Control insects and disease
to prevent leaf loss.
"During the summer I get calls from gardeners about leaves
curling up on their tomato plants," he said. "This is not a disease. It is a
physiological condition that happens after heavy rains. It occurs on the older
leaves. Some tomato varieties are more susceptible to "leaf curl" than others."
"Catfacing" occurs on
tomatoes exposed to cool night temperatures during flowering. Fruits are
misshapen and have scars and holes on the blossom end. Older and large tomato
varieties are more susceptible. The tomatoes are safe to eat.
White spots on the skin of
the tomato are caused by the feeding habits of the stink bug. The bugs stick
their syringe-like mouthparts into the tomato causing the damage.
"I also get calls from
gardeners who cut open a tomato and find hard white areas inside the fruit," he
related. "Warm temperatures during the ripening period cause this condition to
develop. Just cut the affected areas out. Some varieties are more susceptible
to this condition than others."
recommended checking tomato plants for signs of leaf spot diseases such as
septoria leaf spot or early blight. The yellow or brown spots occur on the
lower leaves first. Remove the infected leaves to prevent further spread. For
control of tomato diseases, remove old tomato plant debris from the garden
before planting, avoid wetting the foliage when watering and buy disease-resistant
Tomato hornworms are large, two-to three-inch-long,
green caterpillars with white stripes on the body. A horn protrudes from the
top rear end of the worm.
"Tomato hornworms feed on the leaves and fruit and can quickly
strip a plant of leaves," he said. "Populations can vary from year to year.
Some years, when populations are small and blend in well with the tomato
foliage, you may not see them.
"Last summer, a couple of tomato plants planted in our Smart
Home garden at the Chicago Museum of Science and Industry were stripped of most
of their foliage. We picked 40 hornworms off the plants."
Handpicking is the best and easiest control. If you see
hornworms with small, white cocoons protruding, leave them alone. These cocoons
are the pupae of parasitic insects that help control the hornworm population,
and the worm with the cocoons is doomed.
quality tomatoes develop when temperatures average 75 degrees F. Tomatoes may
get mushy and not ripen well when temperatures are above 90 degrees F. During
hot weather, pick tomatoes when they have a pink color and let them ripen
indoors. This practice will also save the tomatoes from squirrels who like to
take a bite out of ripe ones.
tomatoes, place them in a paper bag, stem end up. Punch several holes all
around the bag and fold the top over. The bag will help to keep some of the
natural ethylene gas in place, which aids in the ripening process. Depending on
how underripe they are, tomatoes may take one to five days to ripen. Check them
daily. You can also wrap individual tomatoes in newspaper for ripening.
"Do not store
ripe tomatoes in the refrigerator," he cautioned. "Flavor and texture begin to
deteriorate when the temperature drops below 54 degrees F. Temperatures above
80 degrees F cause tomatoes to spoil quickly. Store ripe tomatoes at room
temperature for two to three days, away from direct sunlight until ready to
information about vegetable problems, check out the University of Illinois
Extension website: Common Problems for Vegetable
Source: Ron Wolford, Extension Educator, Horticulture, firstname.lastname@example.org