More Problems with Seedlings :(

Just wanted to touch base with you to tell you that everything worked and we are well on our way to healthy cuttings. Thanks again.
I have one more question and I won't bother you anymore. I recently have tried to propagate some seeds. Everything works well until they are about 4 inches high and then they collapse (fold in half) in the middle of the stem and die. I don't know what is causing this as the new seedlings look healthy. It hasn't happened on all of the seedlings, about half. Should I support them with a plastic straw until they are big enough to support themselves. Any ideas you have would be greatly appreciated.

There are two possible reasons for the collapse of the seedlings. One is lack of light. If light level are too low then the seedlings will "reach" for the available light by elongating too much. Eventually the stems get too weak to support themselves and they collapse. The solution is to move them a brighter location or to provide supplementary artificial light, preferably grow lights. For more information about light and growing herbs indoors see the "Magazine Rack" section of our website.
The other possible reason is damping off. Damping off is a fungus disease that attacks the stems of seedlings. Infected stems appear constricted near the soil surface, and the water supply to the leaves gets cut off. Almost overnight infected seedlings can fall over. The solution is to increase ventilation, be more careful with watering (not to water at night, for example), and not to crowd seedlings too much by sowing seeds to thickly. An application of cold chamomile tea helps to arrest the spread of damping disease.