How Long Do Tomato Plants Live?

It Depends

• How long your tomato plant will live depends on the type of tomato plant you select and where you live. In U.S. Department of Agriculture hardiness zones 2 through 10, tomatoes are considered "tender perennials" and grown as annuals. Unless you live in the southernmost zones, outdoor tomato plants will die when the the first frost hits, and your tomato plant's lifespan will be tied to the whims of Mother Nature. Another factor indicative of a tomato plant's longevity is whether it is a determinate or indeterminate variety.

Determinate Varieties

• Tomatoes can be divided into two groups: determinate and indeterminate. Determinate varieties are "programmed" to grow to a predetermined, compact size — about 3 feet to 4 feet — then bloom and fruit just once during a growing season, over a one- to two-week period. Determinate tomato plants live just a few months, and no amount of tending, hoping or wishing will extend their lives. Gardeners who want a large crop of tomatoes all at once, perhaps for preserving, might choose to grow determinate tomatoes.

Indeterminate

• Indeterminate varieties, on the other hand, have no DNA-determined lifespan and can offer their bounty for many years under the right conditions. For example, tomato plants grown in the southernmost regions of the U.S. or in other areas unaffected by frost can live for years, offering their flavorful bounty again and again. Or if you grow an indeterminate tomato in a container and bring it indoors when temperatures drop, your plant will continue to thrive and produce. Some gardeners in mild-weather areas have had luck, too, protecting their tomatoes from the occasional frost by using row covers or blankets.

Maximizing Potential

• No plant will grow very long, of course, if it is not well tended. To get the most of whichever tomato you plant, give it lots of care. Tomatoes love heat, so after mixing rich compost into your soil, put your plants in a spot that gets at least six hours of sun a day. When planting, bury a good portion of the stem and the first set of leaves — this allows the plant to send out more roots. Stake or cage your tomatoes at planting time so that you don't damage the roots later. Water young plants enough so that their roots don’t dry out. As plants grow, soak your tomato garden once a week or every five days when it's really hot.