Ornamental grasses come in many forms, from stately, feathery grasses, to smaller tufted varieties. They’re aquick and attractive way to add color, texture and form to a whole host of garden designs. However, if you decide to change your garden’s planting style, they can also be difficult to remove. Their hardy nature can make them difficult to manage. In fact, they can take over an entire bed if they aren’t regularly tended.
This guide will provide you with a few reliable methods for removing ornamental grasses from your garden. We’ll also talk about planting strategies that you can implement to prevent these plants from becoming a problem in the future.
Some types of ornamental grasses are classified as invasive. For example, in California, fountain and pampas grass are both considered invasive. Always consult your extension office before attempting to get rid of ornamental grasses that fall into this category. You may be required to use specific tools, or have a specialist undertake the work for you.
1. Digging up Ornamental Grass
Established ornamental grasses can have large, complex root systems. This makes digging them up a difficult process to complete successfully.
Firstly, cut the ornamental grass down to about 2 inches above the ground. This allows you to clearly see the plant’s spread. If the spread is particularly large, use a sharp shovel to divide the grass into several sections. Breaking it down like this enables you to remove a section at a time.
Once you can clearly see the plant, force a shovel into the ground beneath it. Make sure that the shovel is completely underneath the plant’s root system. Then pull the shovel up, scooping out the grass. This technique allows you to take up ornamental grass in large clumps.
If you find that the ornamental grass is hard to dig up, try drenching the roots with water. This softens the roots, and the surrounding ground, making it easier to manipulate and dig up the root system.
Dispose of invasive ornamental grasses in accordance with local laws. If the ornamental grass is not considered invasive then you can dispose of it in your green or garden waste or in your compost pile.
Regardless of how well you think you’ve removed the root system, ornamental grass can be incredibly stubborn. Don’t be surprised if, the following spring, new shoots emerge. While this is frustrating, it does give you an indication of where the roots you missed the first time are. Simply dig out the roots, as above.
The area should now be completely free from ornamental grass.
2. Using Herbicide to Remove Ornamental Grasses
Herbicides are an effective way of removing ornamental grasses, grassy weeds and other problem plants.
Glyphosate is a particularly effective herbicide, and careful application in a spray will concentrate the chemicals onto just the ornamental grasses. Just take care not to spray any surrounding plants, as it’s a non-selective herbicide. As a result, it’ll harm or kill any plants it comes into contact with.
Herbicides that contain glyphosate leave little soil residue. This means that you don’t have to worry about planting new plants in the area.
How to Apply
Most herbicides come in liquid or granular form. Whichever option you choose, read and follow the instructions carefully. This increases the chances of a successful application.
Before applying make sure that you’re wearing gloves, and a long-sleeved shirt. Some people may also choose to wear safety goggles and a mask while using the spray. Glyphosate-based herbicides can be toxic if they come into contact with the skin or are accidentally consumed. If pets touch or consume plants still wet with the application, they may become unwell or drowsy. As such, pet owners may choose to use a different solution.
Before applying, cut down tall or overgrown ornamental grasses. No more than 4 inches of growth should be visible.
Don’t apply the herbicide on breezy days. Even a slight breeze may cause the herbicide to spread onto nearby plants. If you can’t wait for a calm weather day, protect surrounding plants by covering them with plastic sheeting or old bed sheets.
Take Extra Care
To further reduce the chances of accidental plant damage use a spray nozzle that produces large, coarse droplets. These are less likely to drift than fine sprays. Keeping the nozzle close to the ground or plant will also help to prevent accidental drift.
You should also avoid spraying herbicides when temperatures are over 85F. The 24 hours following application should, ideally be cooler than this. Warm temperatures may cause moisture, including herbicides, to evaporate before the plant can absorb them.
Apply just enough herbicide to wet the surfaces. If you’re using granular herbicides, carefully water in after applications. You can purchase herbicides suitable for aquatic environments if the ornamental grass is near a water feature.
3. Homemade Solutions
While herbicides can be effective, not everybody wants to use them in their garden. Luckily your kitchen cupboard holds an effective, secret weapon. White vinegar makes a particularly effective ornamental grass killer. It is also a great natural way of keeping dogs away from your flower beds.
Making and Applying Your own Solution
If the ornamental grass is particularly tall, cut it down to no more than 4 inches from the ground. Dispose of these cuttings immediately, either in green waste bags or on your compost heap.
Fill a spray bottle almost completely with white vinegar, then add two squirts of dishwashing soap. Fasten the lid tightly and shake the bottle, fully mixing the contents. Some people like to add half a cup of salt to further increase the mixture’s potency, but this isn’t necessary.
Spray the mixture directly onto the ornamental grass, fully saturating the visible part. Alternatively, pour the liquid onto the root system. This ensures that it penetrates the root ball.
Be careful. This solution is extremely potent, killing all plants that it comes into contact with. Cover surrounding plants with a sheet and apply the solution on a still, calm day, to reduce the chances of accidental application.
Ornamental grass can be stubborn. You may need to reapply the mixture a couple of times before the plant fully dies. However, in most cases the grass will turn brown and begin to dry out within 24 hours. Once the grass has died you’ll be able to easily dig up the root ball. If removal is still difficult, water the ground thoroughly. This softens the roots, aiding removal.
This method may take longer but is far less labor intensive. Solarization is simply the process of killing the plant by baking the root system.
You will first need to cut the plant down, as close to the soil as possible. Use a sharp pair of garden shears for this, or a weed whacker.
Moisten the soil’s surface with a hose or watering can. While the soil is still damp, cover the area with a piece of clear, plastic tarp. Then weigh the tarp down at the edges with bricks.
Over the next 6 weeks or so, the sun’s rays will penetrate the tarp, warming the soil to over 140F. This will bake the root clump, killing the entire root system along with any other weeds in the bed.
Prevent Ornamental Grass From Returning
Landscape fabric is commonly used as a synthetic mulch. In addition, it’s also useful for smothering weeds and grasses. Once your ornamental grasses have been removed, cover the weeded bed with this type of synthetic mulch. This will prevent your grassy plants from re-emerging.
To plant in the bed, simply make slits in the fabric and then ease your species into the ground. If the bed is already planted, make holes in the fabric for the flowers and such to poke through. You can then carefully lay the fabric around them.
Just keep in mind that landscape fabric isn’t the most aesthetically pleasing garden addition. Covering it with another mulch such as woodchips, or gravel, can improve the aesthetic greatly.
Keep Ornamental Grasses Contained
In many cases, prevention is better than cure. This is certainly true when it comes to removing ornamental grasses.
As we’ve already seen, these grasses can spread quickly and easily, making them difficult to remove. If you want to add them to your garden, try planting them in the ground in bottomless containers instead. Should you decide to remove the grass, the root system will be largely contained, making your job easier.
This trick is also useful if you are still working out your garden planting scheme. Bottomless containers allow you to move plants between areas and beds without causing the root systems too much stress.
Ornamental grasses can be stubborn and difficult to completely get rid of. Often the best option is to use a combination of herbicides and physically digging up the plant. Even then you may need to apply the solution more than once to completely rid your garden of any traces.