Posted: May-27-2005 at 8:57am
I didn't have this problem when I was gardening in the puyallup valley but now that I'm in Seattle I can't keep my leafy greans from bolting... esp lettuce. I've heard shade cloth, straw to keep the soil cool, etc. What works for you folks?
Posted: May-27-2005 at 9:34am
You don't mention varieties. Many lettuces are bred/selected for a time of the year. Those that do well early in cool weather maybe getting a bolt signal from temps or day lengths. Are you harvesting just some leaves or full heads? Stress of all kinds, water/fertility/etc, can also cause a plant to react as in, "I better hurry and make seed while I still can."
Trav lives near Sumner and he may be able to add to this but I would assume that your nighttime temps are much warmer now than they were in the Puyallup Valley. That could be what was speeding the process of plant maturity. You might want to check out the monthly variety recommendations in the Seattle Tilth book, The Maritime Northwest Garden Guide.
Trav also recommends sowing a new batch of lettuce transplants the 1st of every month until Aug or so. This gives you a new group plants to replace the rest.