Last evening, we had a lot of rain, and this morning the white Hydrangea stems on the bush were drooped and "lying low". I know that in time, they will recover and make themselves upright. I find that quite amazing. I remember reading some years ago, how there are certain plant cells in the stem whose "job" it is to straighten the stem, when it has been bent. It had something to do with gravitropic movement, and was beyond me. But I found it quite reassuring that each plant has this contingency plan built in, to recover& restore its stature. This article talks about how we can help in drastic cases where the stem is badly bent or crushed, using tape and splint to aid healing.