when to trim ornamental grasses

Asked March 31, 2017, 11:22 AM EDT

we have karl foerster, giant miscanthus, and red-silver maiden grass. should these be trimmed, and if so, what time of year? we've tried trimming the red-silver to about 6" in early spring, but they did not come back that well afterwards. the others, we've just removed dead stuff from the previous year in the fall. that seems to have worked a little better. neither of these is likely the best way to do this, so we're asking for expert advise. full sun to mostly sun exposure, soil is very clay. after killing some beautiful grasses, we've learned to water seldom, if at all.

thank you!

Hennepin County Minnesota ornamental grass horticulture

1 Response

Thank you for the question. The time to cut them back to the ground is late winter or early spring so do it now. By removing the dead grass, the sun can get to the crown better to stimulate growth. These grasses do like well drained soil so it's not surprising that they didn't do well when watered in your clay soil that holds the moisture. Read what Mary Meyer, University of Minnesota Extension, has to say about growing and caring for your ornamental grasses:

Thank you for contacting Extension.