to resolve the helmet heads try to keep a drop of water on them every couple hours, try to gently leave the drop covering the head. it should open up in a couple days
I live about an hour from SAC. Last year I put mine out too early and caused them to have a late start (too cold in the eve/morn). This year I'm going to wait till the mornings are in the high 50s low 60s before I bring them outdoors. Maybe another 2 weeks or more.