Leggy Lettuce Seedling Problem
I just started some lettuce seedlings for the fall and am having a real problem producing strong stems on the plants. See the photo, these plants are two weeks old and the stems are so thin that they can not stand up on their own.
The seeds were started in peat pellets with 3 seeds in each pellet. They are in my garage under growing lights and I have been keeping the lights no further then 2" away from the top of the plants for 16 hours each day. I had a fan on them for a few minutes each day for the first week to increase air circulation and promote strong stems. Once the plants were around 1" tall they were thinned to one plant per pellet.
I had the same problem last Spring with my lettuce started in the trays. However in the Spring I had the trays in a sunny southern facing window. After the plants were a couple of weeks old none of them could stand on their own due to the thin stems. So, for the fall I decided to try the growing lights but ended up with the same result.
Am I doing something wrong? How do I get strong stems on these lettuce plants?