How do you protect hydrangeas from flattening in a rainstorm?
How to Protect Hydrangeas From Flattening in a Rainstorm
Certified GKH Gardening Expert
A healthy hydrangea should be able to stand up to a rainstorm ok, which indicates to me that yours is "leggy" or has weak stems. Leggy plants normally happen when a plant is not getting enough light. While hydrangea like shade, they do need some shade and if they are in too deep of shade, they may develop weak stems. Another indicator that they are not getting enough light is if you get few or no blooms on the plant.
Another possibility is that the plant is not getting enough nutrients to grow properly and this is resulting in weak stems. If you feel this is the case, give the plant some balanced fertilizer.