Deb, too much water makes the regular Shastas flop over like that. I know it rains buckets where you are and maybe you can't control that, but when I lived in Vancouver BC, I had several clumps and noticed that the ones planted near some big hedge plants (roots stole some water, I'm guessing) didn't flop when the others away from the competition did.
In my daughter's garden in Utah (hot & dry) we always had only one clump that would flop, and it was near the veggie garden, getting watered every day.
