What Happens If You Don’t Cut Back Ornamental Grasses?

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Ornamental grasses add immense value to one’s lawn and are considered the perfect addition in any landscaping venture. This is precisely why they are considered premium additions to one’s garden. Trimming ornamental grass is universally recommended as the spring season starts to roll in.

However, what if you are away on holiday with your sprinklers on auto? Or what if you are injured or for whatever reason unable to cut back the ornamental grasses? So, a question arises; what happens if you don’t cut back ornamental grass? Can you get away with not cutting it at all?

If you don’t cut it, there are two things that will happen. First, the green will start growing through the brown while the old, dead leaves will start to rot away. However, this will also mean longer leaves that will be green from the top but brown at the bottom. Second, the grass will take the form of a poorly maintained shrub and therefore damage your home’s aesthetic appeal – but that’s not all.

What Happens If You Don’t Cut Back the Ornamental Grasses?

What If I Don’t Cut Back Ornamental Grass?

As mentioned above, you will find that the green is starting to grow through the brown. One problem that will create is that the brown will start creating seeds. Once grass has created seeds, there is a very good chance that the grass will die out. When that happens, the grass blades will also start to thin out, giving out a ‘wild’ outlook. 

Also, the seeds will start dispersing with the spring winds. This will, in essence, mean that you will have your ornamental grass growing all across the yard. Your ornamental grass will actually risk becoming nothing more than a weed for you and your neighbors.

You most certainly do not have to cut back the ornamental grass if you are looking to harvest seeds from the grass and get more plants. In fact, many commercial nurseries do just that! However, if you are simply looking to get more of the same plants in a controlled manner, you also have the option of dividing older plants.

How Much Should You Cut Back?

An important consideration that you will need to make is what type of grass you have and how much you need to cut. There are some varieties that may actually end up dying if you prune them too harshly. At the same time, there are some varieties that want you to prune it harshly to maintain its aesthetic appeal. For example, evergreen grasses don’t need to be pruned. Instead, you simply have to pull out the dead leaves as they occur – one by one. We recommend you wear rubber gloves to skip the slimy bit and ensure you get a good grip. Examples include, but aren’t limited to:

Winter Season & Ornamental Grass Pruning

If you experience really harsh (especially out of season) winters, like Texas faced in early 2021, you will find that even the most stubborn ornamental grasses and plants will have their foliage damaged. In fact, many plants might even die out.

When experiencing such winter, we recommend you cut them back until they are only about 3 inches or 7.5 cm from the ground. Yes, this might seem a bit too extreme, which is why you should only consider this option if there is an emergency. Doing this every year can severely impede the plant’s ability (and if you’re a plant mama/daddy like me, their willingness) to grow upwards. Instead, the plant will actually start growing sideways!

Speaking of harsh winters, the answer to what happens if you don’t cut back ornamental grass also depends on where you are. Depending on your zone, it might not make a difference whether you cut the ornamental grass or not. If you have really cold winters, it really won’t matter whether you cut it now since the plant will die in the frost as it is. In this case, you will have to start again as the spring season starts to roll in.

Hotter states face a similar issue except that their winter flowering plants die off as the summer approaches and they have to start anew when winter approaches. However, this doesn’t apply to ornamental grasses.

How to Cut Back Ornamental Grass

As mentioned above, the best time to prune ornamental grass is as the spring season starts to roll in. Now that we know what happens if you don’t cut the grass, let us consider how to cut it.

Ornamental grasses are considered hardier plants and therefore can stand the test of weather in most zones. Furthermore, if pruned and divided properly, these plants can last for years. It is important to remember that after every 2-3 years, you will find that the center of your ornamental grass will start dying out. At this point, pruning won’t do you any good. At this point, you will need to divide the grass into different sections and get 5-6 plants out of 1!

Now, for the trimming. Because these are relatively hardy plants, it is rather easy to trim the grasses. You can even do so if you are just an amateur with gardening sheers/scissors. Here is a list of tools you will need:

  • Pruning shears or any other gardening scissors. Larger shears will be more useful here.
  • A spade to redistribute and air the soil
  • A garden hose with a shower head

Cutting Back Ornamental Grasses

How Do You Rejuvenate Ornamental Grass

When cutting deciduous ornamental grasses, you will find that there are three parts of the clump you need to take care of. If you tied off the grass before the winter, you have the option of simply cutting the grass completely about 7.5cm above the ground (if it was an extreme winter) or just cut the top two-thirds of the cool season grass, leaving just one-thirds behind.  

We recommend cutting the grass while it is bundled together. Try to cut in a straight line while the plant is bundled up. By doing this, you will be able to give the plant a ‘peak’ shape when you open it up. With the deciduous grass, you will have to clean up the dead leaves and flower stalks that you didn’t cut as well.

Look for any spent stems that are starting to brown out. Be very careful that you don’t end up damaging any new growth. The longer your shears, the more difficult it will be for you to cut with precision. Once you have cut the top two-thirds, we recommend you turn to using smaller shears.

You will find that many individuals (and even some experts) will recommend that you pull out the old stems and debris from the ground. While the idea is well-founded that you will also be pulling out dead roots with the stem, there is just one rather significant problem. There is a small chance – a really small chance – that the stem you are pulling on is wound around the root system or another stem’s root. When you pull one out, you will most likely pull out the other as well.

This is why we suggest that you cut – not pull. Remember, anything left underneath the ground will eventually rot away and turn into compost. Yes, there is a risk of ants or bacteria finding their way to that root, but since you aren’t cutting any roots, this shouldn’t be a problem. It only becomes an issue when you are dividing the grass.

And with that, you should have an ornamental grass plant ready to grow and bloom for the upcoming year!

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About Charlie D Paige

Charlie is a massive DIY fan, with dozens of DIY projects under his belt - ranging from tiling to electrics, and concrete pads to walls. Charlie loves tinkering, seeing how things works, the outdoors and playing with power tools... so is it any wonder that he's completed so many DIY jobs over the years?

Charlie loves spreading his hard-won DIY experience with the world via this blog.