Don’t Bother

The astilbe (false spirea, false goat's beard) in the gate bed has had spent blooms on it for awhile, so I did a bit of research to see how to deadhead it. Apparently, there is no point in deadheading astilbe other than redirecting the plant's energy into root growth instead of seeds. Unlike a lot of other perennials, the plant will not respond by producing more blooms. Other plants with the same mindset are russian sage, siberian iris, tall garden phlox and sedum "autumn joy."

Yet, other plants are not deadheaded because they provide birds with tasty seeds. Such plants include purple coneflower, daisies, sunflowers, zinnias, rubeckia (black-eyed susan) and coreopsis.

When looking for a "how to" in pruning astilbe, I came across what seems like a fairly sound guideline for deadheading perennials. You can usually cut the flower stalk down to the base of the plant. Only woody plants such as lavender could be harmed by this approach.