When Can I Transplant My Tomatoes?

Time of Year

• Although it's tempting on those first warm days in spring to put out your tomatoes, don't do it. Tomatoes are warm-weather plants and do not do well if nighttime temperatures are cool. A spring frost will kill tomato seedlings. Wait until your average final frost day has passed and nighttime temperatures average 50 degrees Fahrenheit. Transplanting between May and July is ideal in most areas.

Acclimation

• Before placing baby plants into the ground, acclimate them to outdoor temperatures and conditions. Begin by moving the seedlings outside in a warm location for a few hours each day. Gradually increase the time they are outside during the next couple of weeks until they are outside all day. The first night you leave the seedlings outside, keep them near a wall to keep them warm. During the next several days, move them away from the wall.

Transplanting

• Plant tomato seedlings in loose, fertile soil in a spot with at least six hours of sun a day. Dig the hole deep enough so the bottom two sets of leaves are below the soil line. Planting them deeply encourages tomatoes to put out more roots, which leads to a healthier, mature plant. Water the seedlings daily for the first week. After they've adapted, taper off to watering once or twice a week, depending on weather conditions.

Transplanting Mature Plants

• Avoid transplanting mature tomato plants. Tomatoes have deep roots and digging them up destroys some roots stressing the plant. If you must move your tomato plant, do so as early in the season as possible before they bloom. Once the plants put on flowers and fruit, transplanting depletes energy from fruit production and greatly decreases the crop.