Spindly tomato plants?

Question: I have been afraid to plant the tomato plants which I purchased because of the rain and cold mornings. I have been keeping them inside near a window, but they are getting tall and spindly. Is there anything I can do to help them?

Answer: I likewise have some tomato plants which I have not planted. Except for one or two warm days that we have had, tomatoes do not make much growth in this kind of weather. The same is true for a lot of other warm weather vegetables and flowers.

A number of years ago Horticulturists at Michigan State University discovered a practice nicknamed “diff” for a reverse temperature difference. When plants are given day temperature which is cooler than night temperature, they respond by growing shorter and stockier. I put my plants outside during the daytime where they can get direct sunlight. Then I bring them inside at night where the temperature is warmer than most of the days we have had. Their growth is quite compact and stocky.

If you start this practice, your tomato plants will stop stretching for light. Don’t worry too much about extra long stems on tomato plants. When you plant them dig a trench and bury most of the stem. Tomato plants will form roots along this buried stem and eventually will be more productive. Leaves should be removed before burying the stem.

You could also plant now and use a plastic tent, row covers or Wall-O-Water to create a warmer area around the plants.