Time to Cut Down Those Grasses!

Ornamental grasses flattened by heavy snow

You know those fabulous ornamental grasses we all plant for great winter interest? Well, this is just a friendly reminder that it’s time to cut them down so they can get going with this season’s growth. They’ll grow anyway if you don’t cut them down, but they sure won’t look too nice (surely you’ve seen those poor parking lot ‘Karl Foerster’ feather reed grasses that never get any attention after planting – getting shaggier and more dismal each year with green shoots pressing up through many years of dead leaves? Maybe if we all travelled with loppers in our cars, and we each agreed to cut down just one, we could make a difference!).

Action shot! Giant sacaton halfway through cutting process.

Just a couple of tips – Tip #1: Start with your cool season grasses first. How do you know if yours are cool season? Well, a few of the more popular ones are all of the feather reed grasses (Calamagrostis spp.) as well as the fun little Mexican feather grass (Nassella tenuissima). Blue oat grass (Helictotrichon sempervirens), also known as blue avena, is a VERY early cool season grass. Take a look at the base of the clump, and if you see any green leaves making an appearance now, you have a cool season grass. See the green already showing up in this ‘Overdam’ feather reed grass?

Calamagrostis acutiflora ‘Overdam’ with new foliage coming up in early March.

Warm season grasses will get started a little later (but soon!). Some of the more popular ones include Miscanthus spp., Sporobolus spp. (including giant sacaton), Switch grasses (Panicum spp.), and little and big bluestem (Schizachyrium scoparium and Andropogon gerardi).

Tip #2: Cut them about as far down as you can get them (having two or three inches left is about right). Below is a stand of Mexican feather grass after spring cutting. (Oh it was so pretty!)

Nassella tenuissima after a good spring haircut.

Cutting the grasses down may make your garden look a bit bare at first, but in no time at all, your grasses will be back up and beautiful!

Contributed by Carey Harrington, Certified Colorado Gardener, Colorado Native Plant Master