Back in March I wrote a post about cutting back Karl Foerster feather reed grass. Just like those television shows that follow up with child actors later in life, let’s take a look at how these ornamental grasses are doing today. After all, which actions you take in spring will affect how healthy and attractive these plants are down the road.
Here’s a video I posted about the best ways to cut ornamental grasses back in spring. These methods work great for Karl Foerster.
No action taken
Here’s what Karl Foerster grass looks like if it’s not cut back in spring. The new leaves simply grow up into the old, dead growth.
Keep in mind the brown stalks are completely dead. They will never green up ever again. That’s why I recommend removing them as close to the ground as possible between February and March.
If you have a Karl Foerster grass that wasn’t cut down in spring, you have two options. The first option is to leave it until next spring, when you can cut it down to the ground.
The second option is to cut it to the ground now. It’s likely the grass will slowly grow into a green mound before the fall, which will give it a tidier appearance eventually. However, it probably won’t have time to produce seed heads before winter arrives. It will just be a mound of leaves. You could then cut it back in spring, which will allow the grass to grow normally from then on. This is a better option if you don’t think you can tolerate the current state of affairs all the way until next spring.
Cut a foot above the ground
It’s extremely common to see ornamental grasses cut about a foot above the ground in late winter. I’m not exactly sure why this became the standard practice in Colorado, but here are the results.
Early on, the new leaves start to grow up into the old growth, but then they reach a point where they are taller than last year’s growth. The result is a mixture of brown stubs and green growth. I think these plants could look better.
Later in the summer, you notice that the stalks that have grown this summer are beginning to flower. But look what’s very noticeable on each one of these grasses. Yep, last year’s growth. Cutting back ornamental grasses too high above the ground detracts from their appearance for the entire year.
Cut to ground level
Ah, the eye can rest. When Karl Foerster feather reed grass is cut as close to the ground as possible, you remove as much of last year’s growth as possible. The result is new leaves growing without anything blocking them. The plant looks green, attractive and healthy. It will still achieve its famous upright form and gorgeous blonde seed heads. It doesn’t need last year’s growth to hold it upright; it naturally has strong stems.
So early next spring, revisit these results. Give cutting back to the ground a try for beautiful results next summer.