Rock gardens are a fabulous element of surprise to spice up your yard. They add depth and dimensions to your garden as well as an earthy appeal.
In addition, rock gardens are low maintenance and save a lot of water!
Today’s question is how to stop pesty weeds from growing in between these beautiful rock displays.
The most effective way to stop weeds from growing in rocks is to lay a layer of water-permeable landscape fabric beneath the rocks and create 3-to-4-inch steel or wood edging borders around the rock beds.
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In addition, use hand weeding, herbicides, and weed flamers to kill existing weeds effectively.
So, your rock garden is once again infested with weeds after last week’s rain shower. It seems pretty unfair, doesn’t it?
Well, fortunately, we have a few tips on how to stop weeds from growing in rocks. So, let’s have a look.
- What Causes Weeds to Grow in Rocks?
- How to Stop Weeds From Growing in New Rock Landscapes
- How to Prevent Weeds Growing in Existing Rock Landscapes
- Natural Ways to Kill Weeds in Rocks
- Final Thoughts
What Causes Weeds to Grow in Rocks?
Landscaping rocks create a natural, budget-friendly, and low-maintenance, beautiful garden display.
Unfortunately, even though rocks tend to be low-maintenance ground covers that help smother most unwanted plant growth, stubborn weeds still find a way to intrude!
Without regular cleaning, the rocks trap leaves that later turn to soil pockets, resulting in a perfect spot for weeds to thrive.
In addition, dust and bits of organic matter settle in the rock grooves, providing a germination zone for unwanted seeds to sprout.
If weeds are growing in a freshly rocked bed, my best guess would be that you used fine gravel or the stones were dirty when laid. In order to grow, weeds need something to root into; fine gravel allows for weeds to embed themselves.
Lastly, unwanted seeds can be blown into the gaps between the rocks when rocks are packed adjacently, causing weeds to grow.
How to Stop Weeds From Growing in New Rock Landscapes
Weed prevention should start before laying your rock bedding.
So, if you’re laying a new rock garden, do yourself a favor and prepare the area properly- you’ll thank yourself later!
1. Start With a Clean Sweep
The best base for a rock landscape is a weed-free patch (obviously). So, step one is to inspect your area and to get rid of the existing weeds.
- Cover the landscape area with a plastic sheet and leave it covered for six weeks. This process will smother all unwanted weeds. Then, remove and throw away the dead weeds. Note: this only works in warm weather.
- If you are in more of a hurry, spray a non-selective herbicide on the weeds. (Avoid spraying on windy days as the herbicide may kill your other plants).
- You can use household white vinegar to kill some weeds; however, it is not very powerful. Instead, consider using horticultural vinegar.
- Pour boiling water on weeds to kill them. However, it is not a practical solution for a large area.
- Salt does work as a weed killer, but it isn’t advisable. Salt will change your soil’s salinity, ultimately killing your existing plants and shrubs.
2. Lay Water-Permeable Landscape Fabric to Prevent Weeds From Growing
Apply a layer of water-permeable landscape fabric over your area’s soil; this will create a physical barrier to inhibit the growth of the weeds accidentally missed during prepping.
Secure your landscape fabric to ensure that it doesn’t move under the rock layer.
Do not substitute landscape fabric with plastic sheets. Plastic prevents air and water from flowing through to the soil. In addition, plastic will result in mosquito breeding grounds.
3. Create a Border to Prevent Weeds From Growing in Rocks
Unfortunately, weeds can still make their way into your rock garden if nothing blocks them. So, create a border around your rock landscape to create a barrier between your lawn and rocks.
An excellent option is to put in a 3-to-4-inch edging border around the rock beds. Steel borders stop unwanted plants, grasses, and weeds from rooting in the rock beds.
The border will prevent smaller rocks from thinning and spreading. In addition, as weed invasion often occurs where rock areas edges have thinned out, the solid border will dramatically slow down weeds from reoccurring.
How to Prevent Weeds Growing in Existing Rock Landscapes
If you already have an existing rock landscape infested with weeds, don’t worry. It’s not a hopeless case, and there are solutions for your rock garden too!
Here are several ways to prevent weeds from growing in existing rock landscapes:
1. Get Your Hands Dirty!
You can prevent new weeds from growing by pulling and discarding existing weeds before they drop seeds. Make sure to get the roots if you pull weeds, or else they’ll grow right back.
Wet the weeds down first – it will make the job a lot easier!
2. Use a Weed Flame Torch to Remove Weeds From Rocks
A weed torch works well to remove weeds from rocks since rocks are heat tolerant and aren’t flammable. Give the weeds a quick blast of heat to kill them.
Be sure to keep the weed torch away from any flammable materials, like wood mulch.
3. Use a Long-Lasting Weed Killer
If the weed growth has spiraled out of control, consider using a strong, non-selective herbicide or weed killer to kill existing weeds and prevent new weeds from occurring for up to 12 months.
Be sure to spray the weed killer on a wind-free day and consider using a cardboard shield to protect other plants when spraying weeds.
4. Lay Water-Permeable Landscape Fabric to Prevent Weeds From Growing
If you have a current rock garden plagued with weeds, move the rocks away and lay water-permeable landscape fabric onto the base before placing them back to their original position.
Landscape fabric does not stop weeds from growing forever. Even the very best landscape fabric will break down after a few years, allowing weeds to grow again.
Organic material will start to build up between the rocks, and weeds grow again. These new weeds can be tough to get rid of because their roots tend to get tangled in the fabric.
5. Cardboard and Newspaper Block Weed Growth in Rocks
If you want an additional layer to block the sun, add a thick cardboard or newspaper layer over the landscape fabric (sunlight encourages weed growth).
Ensure to overlap the newspaper and add several layers to slow down decomposition and minimize potential gaps for weeds to grow through.
Unfortunately, cardboard and newspaper are only short-term preventative measures. Both materials degrade quickly and, therefore, lose their ability to prevent weeds from growing.
6. Add a Border to Prevent Weeds From Growing in Rocks
Install a metal, wood, or plastic border around your rock landscape to prevent grass and weed from growing.
The border will help contain small stones and gravel, keeping the edges of the rock layer from thinning out. In addition, the thicker rock layer will maintain a deeper surface, preventing weed growth.
Natural Ways to Kill Weeds in Rocks
As mentioned earlier, natural remedies like salt, vinegar, and boiling water can kill weeds in rocks.
When utilizing a weed control method, you want an effective and long-lasting solution. So, it’s best to use the more effective ways, including hand weeding, weed flamers, and herbicides.
Weed prevention should preferably start before laying your rocky landscape and should continue with regular maintenance. However, if you already have a rock garden infested with weeds, there are ways to kill weeds.
Remember that natural remedies like vinegar, salt, and boiling water aren’t the most effective ways to get rid of weeds in rocks.
Instead, get your hands dirty and pull the weeds out, lay landscape fabric, create a border, spray a non-selective herbicide, or use a weed flamer to kill the weeds.
I’m sure at least one of these solutions, or a combination, will keep your rock landscape looking as good as new.
Let us know how you stop weeds from growing in rocks – we’d love to see your photos! Share your thoughts, tips, and ideas below.