Maybe put them closer to the lights and put a fan on them.

Linda

Thanks. I forgot to mention that the grow lights are suspended from chains that I can adjust to keep them close to the starts, and I do have a thermostatically controlled fan that comes on when the greenhouse gets above the mid-eighties.

If the lights are T5's or T8's, they can be an inch or two above the seedlings. Another thought is that maybe they need to be replaced. The fan helps to make the stem nice and strong and thick. Usually, they run continuously.

I don't use a fan, but I start my seedlings in a cool basement. The low temperature also helps the seedlings to grow short but stout.

Linda

I haven't given the starts fertilizer before, but will do so next year. I germinate at the recommended temps using thermostatically controlled heat mats set in the low-80s. However, some days the temps can get hotter in my greenhouse after the seedlings start growing, and I can't set them outside due to deer.

I built a new hot frame over the winter and grew my tomato starts there this year. They got full sun from soon after sunrise till late afternoon and they were leggy. I'd guess they each need more room or like trees they'll put all their effort into growing higher than their neighbors. Myself the leggyness doesn't bother me as I'm willing to dig a hole as deep as my spade and transplant them deep. Would be different If I was in the business.