How To Keep Your Tomato Plants Thriving All Winter Long

Tomatoes are a popular garden plant because many varieties — like cherry tomatoes — are relatively easy to grow, especially for beginner gardeners. Plus, nothing is better than having fresh juicy tomatoes on hand for a summer salad or fresh pasta sauce. As you probably already know, tomatoes are very sensitive to cold and often die as soon as the first frost hits in winter (and they aren't one of those plants that can be rescued after an unexpected snow). However, what you probably don't know about tomatoes is that in their native environment in South America, tomatoes are actually perennials that produce fruit year-round. So, because tomatoes aren't actually annuals — even though we treat them like they are — if you have a variety of tomato plants that you really enjoy and want to grow again next year, you can actually overwinter them.

In general, there are two ways to keep your tomatoes alive in cold climates, and the first involves bringing the entire plant inside. The second involves overwintering small cuttings of your favorite plants. No matter which method you choose, it is important to know that tomatoes are a little fickle when it comes to overwintering and some plants may not make it through to the next season. However, if you are successful and are able to keep your tomato plants alive through the winter, you will be able to start out the spring with mature plants that can produce fruit much earlier than their newer counterparts.

The first step in successfully overwintering tomatoes is to make sure that you choose healthy plants. Near the end of the growing season, tomatoes sometimes develop different plant diseases like bacterial and fungal infections (which is why you shouldn't grow tomatoes and other nightshades like potatoes near each other). Tomato plants that have contracted any one of these diseases will not survive the winter and may even go on to infect other plants. You should also check your tomatoes for any insects and spray the entire plant down with a hose before bringing it inside.

Typically tomato varieties that are more wild or have been made to be resistant to cold weather do better when brought inside in pots. Even so, tomato plants overwintering as full plants inside will need plenty of light and many even require grow lights. You should water tomatoes a lot less in the winter and never fertilize them. Before returning the plants outside in the spring, you should cut them back by about half and slowly reintroduce them to natural light and air.

For some people, it may be easier to overwinter tomatoes from cuttings. To do this, you should find a good sucker (a shoot growing between the stem and branches) and cut off a portion that is about 15 to 30 centimeters long. Then, place the cut end of the sucker in a glass of warm water. Make sure to replace the water with fresh clean water often and let the cutting sit until it starts to grow roots. Once that happens, you can transplant the cutting into a pot under a growing light. And then, by the time the growing season starts in spring, your tomato plant will be well ahead of everyone else's.