Where's the Beefsteak?

In Arlington, Liz and Ken Walsh planted two beefsteak varieties, a smaller hybrid and four cherry tomato plants. They allowed a couple of volunteer seedlings to grow. They picked "pints and pints" of cherry tomatoes, but only five of the full-size fruit.

They had 10 more going, but those were eaten by an animal that Liz Walsh thinks was a vole. As August became unbearably hot and dry, she concedes, she didn't stay on top of the weeds.

"The weather was so variable, and it had a negative effect," said Jon Traunfeld, a fruit and vegetable specialist at the Maryland Home and Garden Information Center. "Everything was slow getting started, then we got a lot of rain, and then it pretty well turned dry in July and August. Unless somebody had pretty decent soil and really took care of their plants, it was below par."

There are ways to minimize problems with tomatoes. Use deep, rich soil with sufficient calcium and organic matter. Apply mulch to keep down weeds and blight spores. Make sure you have sufficient staking to keep vines upright and sufficient spacing to minimize fungal diseases. Also helpful: perhaps a little afternoon shade to reduce the risks of sun scald on the fruit.

Chances of success also are increased with soaker hoses or drip irrigation that moisten the soil but keep water off the leaves, as well as the diligence of the gardener to keep abreast of pests and diseases. Even with mulch, says Traunfeld, blight is such a problem that spraying is needed to keep plants clean and healthy, and copper sprays are organic and effective.

But there are some things the gardener cannot control. Tomatoes like it hot, but not the heat of Washington in August. The problem is not just the high daytime temperatures, but the night temperatures, which stress the plant and conspire to kill the blossoms before they can fruit. In the early August heat wave, for example, the lowest the thermometer reached was about 80 degrees.

Flower viability suffers when the daily mean temperature climbs above 77 degrees, said Mary Peet, a professor of horticulture at North Carolina State University. After five to seven days of such unrelenting heat, "not as much pollen is produced, it's less vigorous and less likely to be released by the anthers."

"My sense is, because of global warming, that in 10 of the last 11 years our nighttime temperatures in urban areas have increased," said Traunfeld, "so bloom set is going to be affected."

Peet points out that in warmer North Carolina, tomatoes tend to be grown to fruit in July rather than August, and wonders if that might become the model for Washington. This would mean setting plants out earlier and protecting them on cooler spring nights.

Traunfeld points out that oversize tomatoes such as beefsteaks, oxhearts, Brandywine and other mammoth heirlooms tend to set fewer fruit and then take several weeks to grow and ripen, exposing them to greater risks of problems than smaller, earlier-fruiting varieties.

Liz Walsh, meanwhile, is among local tomato fans in need of encouragement. Part of her wants to forget them, but she realizes summer wouldn't be the same without them. "I hope to get some next year. Hopefully."