Tomato tips for the patient gardener

Have you set your tomato plants out in the garden yet? No? Good for you! You may be avoiding at least two problems that often plague tomato growers in the Rogue Valley — problems that are worsened by setting tomatoes out when the soil temperature is too low.

Yes, I'm well aware that the air temperature has been hot, hot, hot. But that doesn't mean soil temperatures have kept pace, especially if you have clay soil.

Tomatoes are a tropical vine and do not relish cold or wet feet.

Research recently has shown that blossom end rot, which is not a disease, but a culture problem, is encouraged by setting plants into soil that has not yet reached at least 65 degrees. If you grow tomatoes, a soil thermometer is an excellent tool to have. Purchase one at any garden supply store.

Blossom end rot, which appears as a firm black or brown area at the blossom end of the tomato, is caused by the tomato plant being unable to take up enough calcium from the soil to make strong cell walls. This does not mean your soil is lacking in calcium; it means the tomato plant can't make use of it. Sporadic watering practices — which I call the "drown and drought" method — also can interfere with calcium uptake. But putting your tomato in cold soil is a major culprit.

To warm up your soil, put down clear plastic for enough days to get the soil to 65. One reason so many people use raised beds in the Rogue Valley is that soil in them warms up much faster. If you use raised beds, yours already may be warm enough, but check it with the soil thermometer to be sure.

The second problem caused by cold soil temperature is stunting, or failure to thrive. While the plant eventually may recover, it will grow and produce much better if it has favorable conditions in which to grow from the start.

While I appreciate the thrill of the race with your neighbor or friend to see who can produce the first ripe tomato, I don't think it's worth it to risk putting the tomato plant in conditions where it must struggle all growing season. But that's just me.

When you do set out your plants, remember to clip off all the leaves except for the top three or four sets. Then plant it deep enough so those remaining leaves are just sticking out of the ground. All those hairs you see on the tomato stem will become roots and will help to anchor and feed your tomato.

If, in the process of having your tomato plant on "hold" it has become leggy or developed a thin, elongated stem, simply remove the leaves as instructed above, dig a trench, and lay the plant on its side. Within a few days, you will not be able to tell from appearances how you planted it, but it will be much stronger than leaving it to whip in the wind and perhaps break.

One final hint — put your sturdy support cage and your watering system in place when you first set out the tomato, which saves breakage on the plant when you try to do it later.

Oh, and by the way, if you do get blossom end rot on your tomatoes, just cut out the affected portion — they are safe to eat. They're just not as pretty.

Carol Oneal is a past president of the OSU Jackson County Master Gardeners Association. E-mail her at

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