During June July Aug the greenhouse owner uses a special strain of bib lettuce that tolerates higher temperatures in the greenhouse. Water to each row of the lettuce (abt 16 heads) is supplied by a constant flow of water from a small diameter tube. Seed sprouts in a foam block and then each block is inserted into a hole of a 3"-4"wide x 10ft long growing "trays". Water from tybe drains through the tray and exits the end and then is recycled.
Last edited by Bill Cody; 05/18/13 10:11 PM.
