Thursday, May 7, 2009

Upside Down Tomatoes by Dusty M

Have you seen the ads for the hanging planter with a tomato plant growing upside down from the bottom? Last week an out-of-area friend contacted me to ask what I thought about it. Since it’s a timely topic, I thought I might share what, after some research and reflection, I told him.

My friend, who has been raising vegetables only a couple of years, lives in the northeastern U.S. The TV ads caught his attention because he is plagued by slugs and snails, and a suspended container would avoid that big problem. He also has a late frost date that shortens his growing season. He figured he could start a tomato plant in the hanging container in his sunroom, move it outside on warm days, and finally leave it outside after the threat of frost had passed.

It sounded reasonable to me. So when I attended a Master Gardener committee meeting later in the week, I asked my colleagues if anyone had tried growing upside-down tomatoes. None had, but one person reported on a relative’s experience. The tomato plant grew well but it didn’t bear any tomatoes. The relative confessed that she might have given it too much fertilizer, stimulating green growth rather than the development of fruit. (This would be excess nitrogen in the fertilizer formula, rather than phosphorus, which stimulates flowers and fruit.)

I passed this on to my friend, along with some other thoughts on the subject. I don’t know if he has occasional strong winds such as we experience here. But I think his tomato would need to hang in a spot well protected from wind, as mature tomato vines become rather brittle and would snap if the container swung back and forth. Heavy tomato fruit would also fall to the ground.

At the same time, the container should also be located for maximum exposure to the sun. Tomatoes require a minimum of eight hours of sun a day, and more is better. In my own yard, I don’t see a spot that would work, but I can envision a protected south-facing corner in which a tomato plant would be hot and happy. Then I’d have to find a way to hang the container.

I told my friend that a container sitting on the ground might work as well and be easier to situate than the hanging container. He might attach a copper wire or band around the base of the container to prevent the slugs and snails from climbing aboard. I regularly grow tomato plants in a couple of containers, about 18 inches in diameter at the top. A tomato variety adapted to containers has performed well. The fruit is smaller than what I harvest from plants grown in the ground, but they are plentiful and tasty. I haven’t stretched the start of the growing season through use of these containers, but do stretch the end. By moving the containers in and out of the garage to avoid frost and cold nights, I have been able to harvest fruit as late as Thanksgiving. We have plenty of warm autumn sunshine to keep them producing.

Water is a critical element in growing anything in containers. I water my tomato containers every morning, and add a little water-soluble fertilizer when the plant blooms and starts to set fruit. There’s already an alfalfa-based organic fertilizer that I mixed into the potting soil at the time of planting.

Have any of you grown tomatoes in containers – upside down or right side up? How did it go?

Here's a video on how to do it.