Growing tomatoes inside during the cold winter months is moderately challenging. Tomatoes are a summer crop that needs much light and warm temperatures between 60 and 80 degrees to thrive. Recreate their ideal growing conditions inside and you'll be rewarded with healthy plants and ripe tomatoes. Get a jump on the season by starting your seeds outside during early fall and bring them inside when the weather gets cool.
Scout seed catalogs for interesting varieties. Decide what you want in the optimum tomato: fast maturing, heavy production, taste, size or color. Choose tomatoes that stay bushy and compact when growing them indoors. Patio pick, sweet 100 or tomato sweetheart are all good choices.
Use enriched potting soil. Add slow-release fertilizer to the potting soil and a teaspoon of lime to every gallon of soil. The lime helps prevents blossom end rot. Tomatoes grown inside only have the soil within their pot unlike tomatoes grown outside which can spread their roots over a wide area.
Tomato plants with insufficient light inside will grow leggy with a long thin whitish stem instead of a sturdy green stem. Improve the lighting by moving the plants closer to the window or growing under artificial gro lights. Replant the spindly stemmed plants in a new pot and bury the entire stem except for portion with the leaves near the top. The stem will grow roots which improves the health of the plant.
Outdoor insects pollinate the tomato plants. Indoor, you'll have to take over that job. Every morning, gently brush the newly opened blossoms with a soft brush, going from one blossom to the next. Spray the blossoms with a commercial blossom set product. If your home is dry because of central heating during the winter, mist the blossoms so the pollen doesn't dry out before it does its job.
Avoid Dampening Off
Dampening off is a fungus disease that wilts new seedlings and they die. Nothing can be done to save the plant except start over. The fungus is found in old, used potting soil. It's important to use fresh soil when growing tomatoes inside. Seedlings grown inside are more prone to dampening off if they're kept wet rather than moist.