Yeah, I think you're probably going to have to do something to protect your seedlings because I saw it is supposed to be in low 30's. I will cover the snappys I planted out today. And my lettuce.
I (knock on wood) rarely have a problem with damping off now, but I had my share of years with it. I sprinkle some cinnamon on. Not sure if that actually helps or not but someone told me to try it.
