I have an extraordinary show of Heliathus maxilimilliani right now. So gorgeous! But they have totally flopped over a couple of Matilija poppies and a fat Brandegee's sage. Normally I would wait until later in fall to prune those two plants, but I thought maybe I would prune now (hiding their ugly pruned shapes under the sunflowers). Then, when the sunflowers finish and I cut them back to the ground, the poppies and sage would spring right back. Is this clever or will I actually damage the plants underneath?

(In the photo you can see the Brandegee's in front left, and Matilija just barely on middle left.)