Tips for producing vigorous tomato seedlings for transplanting outdoors.
Q. This will be the first year I've tried growing tomatoes from seed; last year I spent too much money on transplants! I could use some tips — namely, when do you start them, and how do you make sure they don't get all gangly in the house?
A. You'll want to have the seedlings ready for planting when night-time temps are at least 55 degrees. Sow the seeds 6 to 8 weeks before the last expected frost date in your area. Use a moist, good quality potting soil and place the flat or pots in a warm spot (up to 80 degrees); the top of the refrigerator is a good place. Keep the soil evenly moist until germination occurs.
Give the young plants plenty of light. When the seedlings emerge, place under bright fluorescent lights or near south-facing windows. The better the light, the stronger the seedlings will be — especially important for tomato plants.
Give them room to grow. If you've started the seedlings in a flat, you'll need to move them into individual pots. Wait until the first true leaves have formed (not the first two little round leaves that appear), then very gently lift them out of their medium by inserting a coffee stirrer or old fork underneath their roots. Handling each seedling carefully by its top, place in moist, well-drained potting soil in a 4-inch pot. Continue giving the young plants plenty of light and regular waterings.
Introduce them gradually to the outdoors. When nighttime temperatures are consistently in the mid 50s (usually a couple of weeks after the last predicted frost date), move the young plants outside. Place them in the sun for a couple of hours a day, gradually increasing the time every day until they're in full sun all day.
Lay them down for best rooting. When you remove them from their pots and prepare to install them in the ground or in a large planter, gently curve the center stem so that the bottom third of the plant is lying in the prepared planting hole, horizontal to the soil surface, and the foliage and top several inches of the plant are above ground. The tomato plant will root along the stem that's buried in the soil, giving the plant a very healthy boost for growing into a vigorous plant.