What should I do with my ornamental grasses in fall? Do they need to be cut back or should they be left standing through the winter months? And what about dividing – can that be done before winter as well?
Ornamental grass care questions like these come in quite frequently each and every autumn season. And as popular as grasses have become in home landscapes, it is easy to see why there are so many questions.
Ornamental grasses really do have a tremendous upside as a perennial plant. Not only are they drought and deer resistant, but pests simply don’t bother them in the least.
Even better, they require very little when it comes to ongoing maintenance. Except, of course, when it comes to cutting them back and occasionally dividing grass clumps that have become a bit too large.
But one thing is for sure, there is a lot of conflicting information and misinformation about when and how to cut back ornamental grasses. The same goes for finding information about knowing the best time to divide them as well.
With that in mind, we thought it was the perfect time to cover the subject of just exactly what should be done with your ornamental grasses this fall – and what shouldn’t!
Ornamental Grass Care In The Fall
When Can Grasses Be Cut Back?
Let’s first tackle the question of cutting back ornamental grasses. For starters, grasses can be cut back in early or late fall. They can also be cut back in early or late spring. In fact, they can even be trimmed down in the dead of winter during a driving snow storm if you so choose.
The point is, the clump style root systems of ornamental grasses are extremely hardy. So much so that they simply do not need any protection from their foliage on top to insulate them from the harsh conditions of winter.
So when is the absolute best time for cutting back? There are actually a few excellent reasons for cutting back ornamental grasses in the fall, or letting them stay up all winter long. And the choice really depends on your situation.
Keeping Grasses Up Through Winter – The Pros
Keeping your grasses up through winter has several benefits. For starters, most varieties of ornamental grasses do not plume until mid to late fall. And when they do, they can be stunning in the landscape all the way through winter!
The large plumes and stocky grass foliage are great for adding texture and interest to an otherwise bare winter landscape. But in addition to their beauty, they also are extremely beneficial to winter wildlife.
Allowing your ornamental grasses to stay up provides much needed protection for all kinds of animals. And the seed heads of those grasses are wonderful for providing birds with food as well.
Keeping Grasses Up Through Winter – The Cons
With all of those pros for keeping grasses up through winter, you might wonder why anyone would want to cut ornamental grasses back in the fall. But, in some situations, there is a need.
Anyone who has ornamental grasses growing in their yard knows the mess that some grasses can create over the long winter months. Especially large varieties with their huge plumes.
As the plume heads and stems begin to break down, they scatter everywhere. And it can make for quite the headache when it comes to cleaning out spring flowerbeds!
For us, it has always been a compromise when it comes to cutting back. With the grasses in flowerbeds and up close around our home, we cut back in late fall to avoid the spring mess. And for those away from the house, we leave the grasses in place until spring to provide a bit of winter interest and food for the birds.
Dividing Ornamental Grasses
Now let’s tackle the subject of dividing grasses. Grass clumps should be divided every three to five years to keep the grasses strong and viable.
Ornamental grasses actually put forth new growth each year from the outer edges of the clump. As the grass clump ages, the center area dies off, with the dead area getting larger and larger with each passing year.
Over time, it leads to a more unsightly grass stand, and one that is less able to stand upright through the growing season. But by dividing every three to five years, this never becomes an issue.
Fall Is Not The Time…
Unfortunately, when it comes to dividing ornamental grasses, fall is not the time for dividing. Unlike most perennial plants that thrive with fall division, dividing grasses in the fall can be deadly for the plants.
With their root clumps split, they are not able to re-establish in the soil. And because of this, the roots freeze out when the cold of winter sets in. The best time for splitting grasses in early spring, just as new growth begins to set forth from their base. (See : How To Divide Ornamental Grasses)
Cutting Back Grasses – A Few Extra Hints
Whether you cut your grasses back in the spring or fall, one of the easiest ways to cut back your grass stands is with a good pair of electric hedge trimmers. Forget that back breaking work with hand shears – hedge trimmers make quick work of sawing right through the grasses with ease. Product Link : Electric Hedge Shears
We usually cut our grasses with a two prong approach. First, we cut off the grass heads up top to remove the plumes and seed heads. We do this so we can keep the out of our compost pile. Unfortunately, the seed heads can create an issue later in the compost.
Next, we cut the remaining stems of the grasses down to within a few inches of the ground. This material is actually great for the compost pile, especially if you shred it up a bit with a shredder or lawn mower.
Here is to keeping your ornamental grasses strong, healthy and beautiful, no matter when you choose to cut them back! Happy Gardening – Jim and Mary.
Jim and Mary Competti have been writing gardening, DIY and recipe articles and books for over 15 years from their 46 acre Ohio farm. The two are frequent speakers on all things gardening and love to travel in their spare time.
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