Here is information that I found at a website: TIP OF THE WEEK: * How to keep indoor seedlings from S-T-R-E-T-C-H-I-N-G Many gardeners try to get a jump on the season by starting seedlings indoors. Which often means spindly, lush growth because the light intensity and harshness of the outdoors isn't there.(posted 9674 days ago)What to do? Not difficult. Just do whatever you can to mimic the outdoors.
1. A light stand or even a fluorescent light fixture works wonders! Put the seedlings as close to the lights as you can. THERE'S NO SUCH THING AS TOO CLOSE. (By the way, I've written a 24-page book on the subject: Secrets of Starting and Growing Seedlings Under Lights which is available elsewhere on this web site. We just made it available to bookstores this season and perhaps we shouldn't be surprised to find that it really is selling well. The booklet was written because there's really no information like it available anywhere that we've found. In Canada, Coles books is carrying it as well as T & T Seeds. We also created a light stand design kit that you can use to build your own warm wood light stand--we hate the expensive metal ones!!! Look for that among our product list. Also available at T & T Seeds.) 2. Put the seedlings into a cool spot at night. Even on the floor next to a cool wall or behind a curtain. 3. Let your plants wilt between watering. 4. Take out your summer fan and let it blow at your seedlings for an hour or two a day! 5. Don't over fertilize. Add a soluble fertilizer (20-20-20) to your watering can about every third time you water. 6. As soon as the temperature gets to about 10 C. (50 F.) outside, take your plants outside for increasingly longer periods each day, starting with an hour. 7. Don't start tender vegetables too early indoors! Tomatoes should be started SIX WEEKS before your plan to plant them outdoors. For cucumbers and melons, THREE WEEKS IS EARLY ENOUGH! Tests have shown you get no advantage by starting them earlier! (Of course, you can start them even earlier if you plan to plant them under KOZY- COATS. That will give you a month or more head start on your neighbours!