Can I keep my tomato plants for next year?

QIt is the second week of November and my tomato vines are thriving and still blooming. I have two plants that have taken over my garden plot. I planted them near the end of April, according to directions from your column several years ago.

In the past, I have just cut them down to plant fava beans. But these are doing so well this year, even more so after the rain deluge in October, that I’m thinking of keeping them.

I did a little research to find out that tomatoes are indeed perennials, but usually die during the cold of winter. Examples I could find of keeping the plants entailed pots that were taken indoors.

What should I do to best preserve these and see what they produce next year? Should I prune anything? Pinch off any blossoms? One plant is an Early Girl, the other some variety of heirloom.

Should I keep just one or both as an experiment?

— Ed Richardson,

San Jose

I’m all for experimenting, and if you have the space and the plants are healthy, I say give it a try.

Tomatoes originated in the Andes, where they grow in the wild as tender perennials, but the original tomatoes don’t look much like the ones we now grow in our gardens. That’s because today’s tomatoes have been cultivated and hybridized and they are meant to be grown as annuals. If you want to keep the plants alive through the winter, you’ll need to figure out a way to protect them from frost. I’d suggest draping them in old-fashioned Christmas tree lights (not the modern LEDs) and investing in some frost cloth. Cover the plants at night when a frost is forecast.

You won’t get any fruit from the plants during the winter, but you can try to force any green tomatoes now on the plants to ripen by removing any flowers, cutting back on water and stopping the use of fertilizer. This will stress the plant and force it to divert energy to the existing fruit.

You also can harvest any tomatoes and put them in a brown paper bag along with an apple. The apple will release a gas known as ethylene, which is necessary to the ripening process. The tomatoes will turn red, but they won’t taste as good as the ones you picked in the summer. Once they’ve left the vine, sugars stop developing and they just won’t have that same vine-ripened flavor.

If the tomato plants survive the winter, then they should thrive when the temperatures warm and the sunshine returns. Focus your efforts on keeping them warm. Don’t do any pruning as that can encourage new growth, which will be extremely frost tender.

I’ve never tried to carry tomatoes from one season to the next, but I did keep a prolific Hatch chile plant from last season. I was late, as usual, in cleaning up the summer garden and by the time I got to the peppers, this one plant was loaded with chile peppers and it seemed a waste to pull it up.

It survived the winter and was a good producer. In fact, I just harvested some peppers from it the other day. I haven’t decided whether or not to pull it this year, but it’s looking scraggly, so I probably will. All plants have a natural life span.