Maine news, sports, weather from Portland Press Herald / Maine Sunday Telegram, Portland, Maine

July 8, 2012

Maine Gardener: After all that rain, you say 'tomato,' I say 'I hope so'

By TOM ATWELL

This might be a tough year for tomatoes -- for me and everyone else. 

It rained in Portland more than tomatoes like -- 8.6 inches according to the National Weather Service, and more than 10 inches according to my rain gauge.

That is a lot of water, and tomatoes do not like having soil -- and the diseases contained in the soil -- splashed up on their leaves.

Nancy and I begin our tomatoes under hoop houses with slits in the plastic, mostly because it keeps the plants warmer, promoting faster growth, and keeps groundhogs and other critters from eating them.

But this year the hoop houses also protected the tomatoes -- and peppers, watermelon and eggplant -- from downpours.

When I took the hoop houses off the tomatoes June 27, I found some problems. A lot of the lower branches on the tomato plants were yellow and withered rather than lush and green. I did find a few small green tomatoes, and some of the plants -- those that I planted in early June rather than late May -- looked pretty good. But I was worried.

Tomatoes are the most important plant to most gardeners, mostly because home-grown tomatoes are vastly superior to anything you buy in the supermarket. And when they are in season we eat them at least two meals a day.

Frank Wertheim, a home horticulture specialist with the University of Maine extension in York County, said there isn't really too much you can do at this point to help the tomatoes recover.

"You do need to recognize that because of all the rain we had, a lot of the nitrogen might have been washed away," Wertheim said. "You might want to add a bit, but not too much. They are probably a little hungry."

Adding too much nitrogen will promote the growth of leaves, he said, and now is the time that you want to promote fruit growth.

He said people who use organic fertilizers are probably better off than those who use pelletized fertilizer because in organic fertilizer the nitrogen isn't released until the temperatures get warm  -- and it didn't get very warm in June.

Pruning your tomatoes will not do anything to help tomato production, Wertheim said. I had cut off the lower branches with yellow leaves on our tomatoes before I called Wertheim, thinking it might improve air circulation.

"Most home gardeners don't prune their tomatoes at all," Wertheim said. "They just put them in a cage and let them grow."

Tomatoes come in two basic types: determinate and indeterminate. 

Determinate tomato plants grow to a certain size and then stop growing and produce fruit. They are favored by commercial growers because the tomatoes all ripen at about the same time and have to be picked only once.

"You don't prune determinate tomatoes because they are a limited size anyway, and you'd just be removing leaves and fruit," Wertheim said.

Indeterminate tomatoes will continue growing until the frost kills them off, and those are the ones you should prune. Wertheim said the best article he had ever read about pruning tomatoes appeared in Fine Gardening magazine by Frank Ferrandino from the Agriculture Experiment Station in New Haven, Conn., and you can find it easily with a Google search. 

Simplified, you want to have one to three main stems on an indeterminate tomato, cutting off all suckers that you do not want to become a main stem. Flowers and tomatoes will be produced close to main stems.

This year we planted some Patio tomatoes, for the patio; two determinate tomatoes, Oregon Spring and Mountain Pride; one indeterminate tomato, Sweet 100; and Rutgers. There are apparently several tomatoes named Rutgers, determinate and indeterminate.

(Continued on page 2)

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