Avoiding Tomato Problems

Yellow sticky traps catch aphids and flea beetles.

Ozarks Gardening; May 3, 2011
Jim Long

Preparing Tomato Beds

The past couple of springs I’ve written about new research  on controlling tomato viruses, from Texas A & M University, and tried their recommended methods. It didn’t control all of the virus problems, thanks to an unusually wet, cool and humid spring we had last season, but I still saw considerable improvements, and will continue with their methods this year.

The methods I use for helping to control tomato virus (often called, “the wilt.”) are as follows. First, I incorporate agricultural cornmeal into the soil early in the year and again just before planting. Whether your local feed store calls it agricultural. cornmeal, or simply ground corn feed, it’s the same thing. Texas A & M has demonstrated that pulverized corn, with some cobs and husks, it’s worked into the soil and causes the growth of beneficial bacteria which attack tomato virus in the soil. I apply 2 lbs. of cornmeal and 1 lb. of dry molasses (which studies show helps the cornmeal work better) per 12 feet of tomato row, poured on top then mixed into the soil.

The second treatment I use, is to mulch the entire tomato bed immediately after the tomatoes are planted. Formerly I’d wait for several weeks to let the ground warm faster, but researchers have proven that putting mulch down immediately, eliminates the splash-up from the soil onto the leaves, and that is how the virus first gets on the lowest tomato leaves. The virus remains in the soil where tomatoes have grown before, and rain splashes the soil, and the virus, on to the lowest leaves of the tomato plants.

Third, I use homemade sticky traps, two for each tomato plant, to trap the aphids that settle in on the tomato plants. It is the aphids that spread the virus (the “wilt), from the bottom leaves upward, by their eating habits. My traps consist of yellow plastic cups, turned upside down and stuck onto 16 inch tall, broomstick-sized sticks, using a thumbtack. The sticks are pushed into the ground about a foot from the tomato plant. I coat the yellow plastic cup on the outside, with Tree Tanglefoot, a very sticky substance that doesn’t wash off. The aphids are attracted to the color yellow and the Tanglefoot catches them.

And last, I begin spraying the plants with Neem oil spray about the second week after planting. Neem prevents the aphids from getting a good start, and kills the eggs and young aphids that can’t yet get to the sticky traps.

To summarize, work the cornmeal into the soil in March, and again in late April; mulch as soon as the plants are in the ground. Then put out yellow sticky traps, 2 for every plant, and within a week of planting, begin spraying the plants with Neem and continue the spraying every 10 days well into summer. This is the best method I’ve found for stopping the wilt and virus problems on tomatoes. (The alternative, which is what old-time tomato growers used, was to plant tomatoes in “new” soil, meaning areas which haven’t had tomatoes growing in them before. That helps cut down on the amount of wilt considerably).

Tree Tanglefoot is available in most garden stores and on-line. Agricultural cornmeal, or its equivalent, pulverized corn feed, is available at most area feed stores. If they don't’ have it, ask them to order it, it’s easily available from their wholesale supplier.  Yellow plastic cups were difficult to find last year, so I used yellow, “water wings,” the flexible foam tubes kids use in swimming pools, cutting them up into 4 inch pieces and they worked as well as cups.

To see photos and links to more information, visit the Ozarks Gardening blog at ozarksgardening.blogspot.com. You can see what’s happening in my garden this week at jimlongsgarden.blogspot.com. Our annual open house for the garden is Saturday, June 18. Call for directions: 417-779-5450. Happy gardening!