By William Terry Kelley
University of
Georgia
They may look beautiful, but those store-bought tomatoes can’t
match the flavor of the ones you pick vine-ripe fresh from your
garden. Unfortunately, it’s getting harder to do that in Georgia,
particularly in the southern two-thirds of the state.
Most of the difficulty stems from a virus that afflicts tomatoes.
Tomato spotted wilt has been in Georgia only a few years. It’s a
major problem for commercial growers in the Deep South, though.
And it’s truly the bane of garden tomatoes in that area.
If you’ve been growing garden tomatoes in Georgia over the past
five to seven years, you’ve probably seen the virus.
How to recognize it
The symptoms vary, but young leaves usually turn bronze and later
develop small, dark spots. The growing tips die back, and the
stems of terminals may become streaked. Some plants may look
one-sided or stunted overall.
Plants that get infected early usually don’t develop fruit. The
ones infected later may have knotty fruit. The more mature
tomatoes may have light-colored ring spots, and green ones may
have bumpy areas with faint, concentric rings. As these tomatoes
mature, the rings get easier to see and turn red and white or red
and yellow.
The bottom line is that you don’t get any good tomatoes from
infected plants.
How it spreads
The disease is spread by thrips as they feed on the plant. And
it’s almost impossible to prevent infection by controlling these
tiny insects. They usually transmit the virus before the
insecticide can kill them.
Tomato spotted wilt has many hosts. It can infect crops such as
peanuts, tobacco and pepper and countless weeds, too.
Commercial growers have ways to reduce the disease and its
severity. Gardeners who try to grow tomatoes in a conventional
garden have a hard time producing a harvestable crop.
Bottom line
So, can you still grow garden tomatoes in the South? Yes, but you
may have to change a few things about how you grow them.
As with almost any virus, the most effective way to control the
virus is to use resistant varieties. A few are on the market now.
You may have tried some of the earlier-released cultivars.
Not all resistant varieties are available to gardeners, though.
The seeds of some come only in large quantities.
The seeds of some resistant varieties do come in small packets for
gardeners, though. “Amelia,” from Harris Seeds (
one of the newest. Some seed companies offer “BHN 444” or “BHN
640” in small packages, too.
Look for plants
Probably the best way to get resistant varieties, however, is to
look for seedlings at your favorite garden center. The seedlings
may not be easy to find, but look for them.
One drawback to using these varieties is that they probably won’t
have quite the flavor of your old garden favorite. They were bred
for commercial production. But let them get ripe on the vine and
they’ll be fine.
Another weapon that seems to help some commercial growers control
the virus is using mulches. Planting tomatoes into black plastic
mulch has been shown to reduce the level of infection over
simple, bare-ground production.
Kitchen option
Reflective silver mulches seem to work even better. These mulches
have to be almost like chrome. Aluminum foil might make a
suitable substitute, since the actual plastic, reflective mulches
are expensive and hard to find.
Keeping weeds in check around the garden may help some, too. Some
growers have even tried tying reflective streamers to the tomato
stakes, with the idea that they confuse the thrips so they don’t
land on the tomatoes.
Growing tomatoes in home gardens isn’t what it used to be. To
keep those fresh, vine-ripe tomatoes coming, though, try these
resistant varieties and changes in tactics. Hopefully, the days
of growing home-garden tomatoes are far from numbered.
(Terry Kelley is an Extension Service horticulturist with the
University of Georgia College of Agricultural and Environmental
Sciences.)
