If weeds are invading your rock landscape features, attack them with a weed killer that simultaneously kills existing weeds and prevents new ones from sprouting. If possible, install a layer of landscape fabric beneath rocks to prevent weed regrowth. Installing a border around areas landscaped with rock helps stop invasive weeds and grasses from moving in. Finally, you can remove weeds naturally by hand weeding or by using a flame weeder.
Table of Contents
5 Tricks For Killing Weeds in Rocks
Invasive weeds can destroy the look of your rock beds, and where one weed invades more are sure to follow. When possible, act fast to wipe out invasive plants. With a few tricks, you can kill the weed growth among your rocks and prevent weeds from coming back. Just employ these simple methods:
Use a Long-Lasting Weed Killer and Preventer Spray
To wipe out weeds in rocks, use a strong weed spray that kills weeds down to the root permanently and prevents new weeds from growing. Because it’s unlikely that you want any plants growing up through your landscaping rocks, this is a great application for long-lasting weed killers.
- Use this weed killer that attacks all types of weeds and grasses and prevents regrowth in the treated area for up to 12 months.
- When applying weed killer spray, make sure only weeds and invasive grass are treated.
To prevent overspray that may harm desirable plants and grasses, apply weed killers on a wind-free day. If necessary, use cardboard to shield desirable plants when spraying weeds.
Lay Landscape Fabric
A layer of water-permeable landscape fabric beneath rocks creates a physical barrier that prevents weeds from sprouting. If you are planning a new rock installation, lay landscape fabric on top of the soil. If your rocks are currently being plagued with weeds, move them to the side and lay landscape fabric before moving the rocks back to their original position.
- This landscape fabric can prevent weeds from sprouting up beneath rocks.
- Lay landscape fabric before installing rocks in a new area.
- If rocks are already present, rake them aside, lay landscape fabric, and then return the rocks to their previous location.
- Use water-permeable landscape fabric to create a weed barrier. Non-permeable materials, such as plastic, can trap water. This leads to flooded areas and attracts pests.
Do not substitute plastic sheeting for landscape fabric. Plastic prevents air and water from reaching the soil. This causes water to pool among your rocks, which can create a breeding ground for mosquitoes and other insects.
Install a Border
A landscape border around rocky areas can help prevent invasive weed and grass roots from entering rock areas. In some cases, the weeds you see cropping up in your rocks are sprouts from roots or runners. A landscape border works as a physical weed barrier and reduces the number of weeds among rocks.
- Install a solid landscape border around rock areas. Metal or wood makes for good choices.
- A solid border prevents weed and grass from invading your rocks.
- A border helps contain small rocks or gravel. This keeps the rock layer from thinning out at the edges, maintaining a deep surface that resists weeds.
Often, weed invasion begins at the edges of rocky areas where rock or gravel has become dispersed and thin. Weeds and grasses have a much easier time getting a foothold in these thin areas. A solid border around your rocks keeps them contained. This prevents rocks from spreading and thinning, maintaining a deep rock layer that resists weeds.
The best way to kill weeds down to the root without using herbicides is by hand-weeding. This may seem like hard work, but no home remedy is as effective as hand weeding. If you use the right weeding tool, the job can be much easier.
- Remove weeds along with their roots to kill them completely.
- Discard weeds immediately to prevent them from dropping seeds after they’ve been uprooted.
When pulling weeds, bag and trash them immediately. Weeds left on the surface can attempt to re-root or they may drop weed seeds. Because weed seeds can survive composting, it’s best to treat all uprooted weeds as trash.
Flame weeding is a great solution for killing stubborn weeds in landscaping rocks. Because there are usually few desirable plants growing near your rocks, you can use the superheated air created by a flame weeder to kill weeds without much risk to other plants.
- Flame weeders kill weeds without the use of any herbicides.
- To use a flame weeder, pass the flame 3–6 inches (7.5–15 cm) above the weeds. The superheated air kills the weeds in 1/10 of a second. It will wilt within hours and be fully dead in a few days.
- Do not set fire to the weeds or touch the flame directly to them. This is both unnecessary and dangerous.
Always check conditions before using a flame weeder. Although correct use of a flame weeder never sets fire to weeds, accidents can happen. Do not use a flame weeder during a drought or in regions where brush fires are common.
Methods to Avoid When Killing Weeds in Landscape Rock
Several popular “natural” methods are touted as solutions for killing weeds in rocks. Some of these methods are ineffective, while others can be more dangerous to your yard than herbicides. Be wary of the following weed killers.
- Salt: Salt poisons the soil and can prevent any plant regrowth for months or years. Additionally, salt is easily carried through the soil by water. If you apply salt to a rocky area to suppress weeds, there’s a very high chance that runoff water will carry the salt to nearby plants and grass, killing it. Long-lasting herbicides are designed to bind to the soil to prevent this runoff kill. Salt can cause more problems than a herbicide.
- Vinegar: Weed killers containing white vinegar, apple cider vinegar, or even high-strength horticultural vinegar are not effective at killing weeds and grass. Vinegar only kills the aboveground portion of the plant but does not attack roots. In most cases, the weed will regrow a few weeks after vinegar application.
- Boiling Water: Similar to vinegar, boiling water only attacks the aboveground portion of weeds. Soil absorbs the water over several minutes, preventing it from penetrating to the roots while it’s still hot. You can kill small, immature weeds with this method but tough grass and dandelions will bounce back quickly.
When employing a weed control method among your rock landscaping, you want a solution that lasts and doesn’t cause any unintended harm to nearby plants. Be wary of homemade weed killers—vinegar and boiling water are far less effective than hand weeding.
Should You Put Landscape Fabric Under Rocks to Stop Weeds?
If you are planning to install rocks in a new area, it’s a great idea to lay landscaping fabric first. The landscape fabric will form a physical barrier that smothers any weed seeds that try to sprout. Weeds will be unable to push through the fabric and will die. Plus, any weed seeds or runners that find their way into your rocks will not be able to reach the soil to take root.
- Lay landscape fabric beneath landscaping rocks whenever possible.
- Acts as a physical barrier that smothers sprouting weeds.
- Prevents any weed seeds blown into a rocky area from reaching soil and sprouting.
In many cases, a simple installation of landscape fabric is all you need to keep your rock landscaping weed-free. This is a great long-term weed solution.
How Do You Keep Weeds From Growing in Stones?
If weeds have taken over an area landscaped with rocks or stones, the best methods to get rid of weeds and prevent their return are:
- Spray weeds with a high-power weed killer that prevents weed regrowth for the next 12 months.
- Install a layer of landscape fabric beneath the rocks.
- Construct a solid border around your rocks to keep them contained and thwart invasive weed roots.
- Hand pull weeds to kill them to the root without herbicides.
- Use a flame weeder to safely kill weeds in 1/10 of a second.
These methods allow you to kill and suppress weeds with or without the use of herbicides. More importantly, they’re effective. “Homemade” weed killers with white vinegar will not kill weeds to the root, so it’s best to employ permanent solutions.