I have 3 beautiful bushes by my house, morning and early afternoon sun. They are perfect until it rains, then the heads droop over to the ground. I have put twine around the middle of the bush to help keep them upright. This only keeps them off the ground. My question is how do I help the plant build a stronger stem. I do trim late fall just to remove old flowers, should I trim down 1/2 way to get a stronger base? The plant is healthy and has tons of flower growth. Just looks awful after a rain and it's right by my front door.
This picture is what they looked like before the rain.
