With the right light, you can grow winter tomatoes indoors. … Be prepared for spring! Below are some tips for starting seeds indoors.
Just one encounter with a tasteless, artificially ripened, imported winter supermarket tomato makes you want to grow your own tangy, sweet-tasting tomatoes in the off-season.
It sure did me, and I met with enough initial success and continued refining my technique until now, in a good winter, at peak production, a single plant in my window produces a pint of cherry or pear tomatoes every day or two. Here’s how to do this yourself:
Although many varieties of “compact” bush tomatoes are advertised as good for container production, they won’t perform well over a long winter. These are “determinate” varieties — plants with branches that grow to a certain length and then stop. They produce a finite number of fruits over a limited period — certainly far less time than a long stretch of northern winter.
Better options for indoor winter tomatoes are “indeterminate” varieties — those that continue growing and producing indefinitely. Furthermore, I’ve found that cherry and plum types, bearing small fruits in abundance, are more productive than large slicing types.
Because indeterminate vines bear a blossom cluster at each node, and the stems between nodes grow longer indoors in the dimmer light of winter than they would outdoors in summer, I recommend you choose from among the less-vigorous indeterminate varieties on the market, lest the vine take over the house without bearing much fruit. My favorite choices are old-fashioned ‘Yellow Pear’ and an unnamed, less vigorous red variety that I’ve grown for years, but the red ‘Tommy Toe,’ an Ozark heirloom and frequent winner of taste tests, and ‘Pink Ping Pong’, called “very sweet, smooth and juicy” by heirloom tomato expert Carolyn Male, are worth growing this way, too.
Sufficient light is paramount for successful indoor cherry tomato production. Choose a window as nearly floor-to-ceiling in height and as south-facing as possible. Large picture windows or sunroom exposures are ideal.
A large-enough container will be needed at the outset, too. Choose a 5-gallon container at a minimum — and 10 is even better — to support the rather massive winter-long growth that will accumulate.
To get a head start, you can start your indoor plants from cuttings at the end of the summer. If grown from seed, indeterminate varieties must reach several feet in height before the first blooms appear, so the cuttings save precious time. To start your own, cut a branch from a favorite variety in your garden in late summer, section it into several cuttings, each with two sets of leaves. Clip off all but one leaf at the top and place the whole bundle in a jar of water in a sunny indoor window.