K.T. from Missouri recently submitted this question on our Facebook page:
"We are planning our 'indoor' starters for February... only problem we have is starting our tomatoes - they seem to get up a few inches tall and fall over. :( Any suggestions?"
Hi, K.T.,  the most likely culprit for "floppy seedlings" is that the light source you're using is too far away from the plants. You should be using a full spectrum fluorescent light. There are blue spectrum and red spectrum bulbs available too which have differing affects on plant growth, full spectrum is best. Because fluorescents do not give off any heat you can put them very close to plants. They should be 1-2" away from plants, otherwise plants will stretch (like sprouts) to be closer and become thin and "leggy" and eventually fall over. Growing seedlings need at least 14 hours of full sun, this is seldom achieved with short winter days or in windows since the light filtering in is not usually full. Early winter starts are best done using the fluorescent light. Look for an article on how to build your own seedling starter stand in our January issue of The Seed Bin - our online e-newsletter.  (Not receiving The Seed Bin? Sign up here!)