Editor's note: This is Part 1 of a two-part series on growing tomatoes and focuses on choosing the best seeds and plants. Part 2 on common tomato problems and how to deal with them is planned for March 30, about the time those problems start showing up.
Home vegetable gardening means homegrown tomatoes. At this time of year, one of the most important questions a tomato gardener must ask is, which variety to grow? With renewed interest in home gardening, there are many new tomato varieties available.
From the perspective of a home-gardening plant pathologist, disease resistance is an important trait of trouble-free tomatoes. Resistant tomatoes are hybrid varieties with specific genes that allow them to naturally fend off attack by disease-causing agents.
Tomato problems commonly found in the Lowcountry include these three: fusarium wilt (F), root-knot nematode (N) and tomato spotted wilt (TSW).
Leaves on one side of tomato plants that turn golden yellow before wilting are indicative of fusarium wilt.
Roots infected by the root-knot nematode are covered with small swellings or "knots."
Tomato spotted wilt can affect all susceptible varieties of tomatoes, including grape. Spotted wilt is not a wilt disease; it causes brown or bronze-colored blotches on leaves and fruit.
Tomato spotted wilt is a virus disease carried by thrips, tiny insects that feed on tomato leaves and blossoms. Tomato plants infected when young will be stunted and not produce any fruit. Plants infected when they are older produce spotty fruit that does not turn fully red.
To start transplants from seed, gardeners should purchase seed this week and sow it next week, or at least six weeks before transplanting in early April.
Here is a short list of some varieties that should perform well in our Lowcountry climate. (All of these varieties are conventionally bred and not genetically modified.)
Do it yourself
Tasti-Lee (tasti-lee.com) is a new, flavorful, round, red tomato developed by accomplished breeder Dr. Jay Scott at the University of Florida. He named it for his mother-in-law, Lee, who wanted a tasty tomato. My family enjoys Tasti-Lee fruit purchased from supermarkets. Now anyone can grow this tomato with seed from W. Atlee Burpee & Co. (burpee.com). Tasti-Lee was bred so fruits ripen on the plant without starting to rot or soften.
BHN-1021, a round, red variety, and BHN-968, a red cherry variety, are resistant to the big three: fusarium wilt, root-knot nematode and tomato spotted wilt. These varieties are offered by Johnny's Selected Seeds.
Plum Regal, a plum or sauce variety from another renowned breeder, Dr. Randy Gardner of North Carolina State University, also has resistance to spotted wilt. It has the added advantage of resistance to early blight, the most common fungal leaf spot on tomato. It is available from Johnny's.
The easier way out
Gardeners who want to buy reliable, disease-resistant transplants should look for these round, red varieties at local retailers.
Amelia, a widely grown, flavorful tomato with resistance to F, N, and TSW.
BHN 602, a variety favored by local growers, with resistance to F and TSW.
Big Beef, one of the best beefsteak or large-fruited (12-ounce) varieties for the Southeast that is resistant to F and N.
Celebrity, a popular home garden and farmers market variety for 30 years, well-known for its classic flavor and resistance to F and N.
One variety that is not suited to the Southeast is Cherokee Purple, an heirloom that is very susceptible to gray leaf spot disease. This variety can act as a "magnet" for gray leaf spot that will spread to other heirloom tomatoes. Hybrids are resistant to this disease.
To graft or not
Heirloom tomatoes can be grafted onto special rootstock varieties that are disease-resistant. These rootstocks are resistant to fusarium wilt and nematodes, so that susceptible heirlooms can be grown without becoming infected. During grafting, the top half of a tomato seedling is clipped to the bottom half of a rootstock seedling. The two halves grow together in about a week.
If you want to grow a few grafted tomatoes, it is cost- and time-effective to buy grafted transplants. Several seed companies sell grafted heirloom tomato transplants. Videos on how to graft are available at www.vegetable grafting.org under the Resources, Prepare menus.
The recommended varieties mentioned here have "good genes" and a proven track record, the first step to trouble-free tomatoes.
Anthony Keinath is professor of plant pathology at the Clemson Coastal Research & Education Center in Charleston. His expertise is in diseases of vegetables. He also is an avid gardener. Contact him at tknth@ clemson.edu.