I don't consider them fragile at all here. However, in hot weather they die back. We are having a "late" spring, so the foliage is still up and attractive. Here they bloom in March or early April and can seed out, so I usuallly have babies to take to plant swaps.

Sorry you are having problems.

I do find them fragile to human handling. When I'm moving them, I often break off outside leaves. But once in the ground, they stand up to people and animals brushing by pretty well. And boy, do they self seed.