What to Put Under Rocks to Prevent Weeds From Growing?

Our team independently selects, reviews, and identifies the best products. We may earn affiliate commissions on purchases made from links on this page. Read about our links here. This post was updated on March 18, 2021

One of the most difficult parts of maintaining a garden or a lawn is the fact that weeds always seem to spring up from everywhere, no matter how hard you try to get rid of them. One of the places where weeds are most likely to grow is under your landscaping rocks—those beautiful pieces you place to add a special touch to your lawn or garden. Wild violet is just one of many weeds that are perfectly capable of appearing in between your landscaping rocks.

Preventing weed from growing under your rocks involves just a few easy steps: preparing your garden or lawn by getting rid of the weeds that are currently there, and laying a weed barrier between your rocks and the soil. If you do it the right way, it will keep your garden neat and weed-free for a very long time.

Preparing the area for landscaping rocks

Before you start laying out your landscaping rocks and positioning them just the way you want them, you have to make sure that the area is weed-free. If you have rocks in place already, the best you can do is to temporarily rake the weeds away or pick them by hand. If you’re working with a clean slate, however, but there are weeds in the areas where you plan to put the rocks, here are some of the things you can do:

#1 Household white vinegar

Using household white vinegar is one of the natural ways to kill off the weeds, although it might not be effective all the time. If you spray some vinegar onto the weeds, there’s a huge chance they might burn. Another option, however, would be to use horticultural vinegar, which is a much stronger substance.

Important note: Make sure you are wearing goggles and safety gloves as vinegar—especially horticultural vinegar—is very acidic and can irritate your eyes and damage your skin.

#2 Boiling water

Another way to get rid of the weeds is to boil a large pot of water and pour it over the weeds. It can be a little bit challenging and a rather impractical solution, especially if you have a large area that is covered with weeds. Make sure you’re wearing boots and gloves so you don’t get burned by the hot water.

While boiling water is not the most practical alternative to actual herbicides, it’s the safest and most environmentally friendly way to kill weeds. It does kill everything that it comes in contact with, so be careful not to splash boiling water all over the lawn.

If you own a steam cleaner, you could also try using it instead of boiling water.

#3 Salt

When salt is applied to weeds, they dehydrate them and cause them to die. Salt is an inexpensive and readily available solution, nevertheless, it must be used with a great deal of caution, according to Gardening Know How.

If salt is poured onto the ground, it can damage the soil and surrounding vegetation, keeping shrubs and other plants from growing. The best way to use salt is by applying it directly to the weed. Make sure you are handling it with care so you don’t rub it in your eyes or accidentally ingest it.

#4 Digging the weeds out

Instead of adding salt or vinegar or any other solution that you are not sure about, you might want to consider digging out the weeds instead. It’s cheaper and faster as all it needs is a shovel. You also don’t have to wait for a few days for the weeds to dry up before you pull them out, as compared to if you were to spray on some vinegar, or salt, or other weed-killing solution.

The best weed barriers to lay under landscaping rocks

Before laying down your rocks, SFGate’s Home Guides recommends that you put a weed barrier between the soil and the rocks. This prevents weed seeds from touching the soil and springing up between your rocks. If you’ve got your rocks in place already, you will have to remove them while you install the weed barrier. Here are some of the most effective ones:

#1 Landscape fabric

ECOgardener Premium Landscape Fabric that blocks the growth of weeds
Check prices and buying options on Amazon

Landscaping cloth serves as an effective weed barrier because it allows water, nutrients, and air to flow to your soil and plants, while generally keeping weed seeds from reaching the soil underneath the rocks. At the same time, landscape fabric works to prevent your rocks from sinking into the soil because of their weight—this is especially effective if you live in an area with frequent, heavy rainfall.

There are three types of landscape fabric that you can choose from, according to Own the Yard. They are the following:

Spun – This is a strong, durable fabric that does not puncture or tear. It has circular or swirling patterns and you may find that you have to cut some holes to let the plants grow and tree roots to spread. The upside is that it is very strong and can last for several years.

Perforated – This comes with pre-cut holes for water and air to pass through. Because it is lightweight, there is a chance it might tear easily.

Woven – This fabric has a criss-cross pattern that allows water and air to reach the soil underneath. If you feel like the holes are too small and cannot accommodate the larger roots, you can always create bigger holes.

Check landscape fabric options on Amazon

It’s important to note that landscape fabric will not be able to keep the weeds away forever. Eventually, organic material will start to build up against the rocks again and the wind will persistently carry over weed seeds that may start to sprout, even under and between your rocks. No matter how good your landscape fabric is, it will break down gradually over the course of its lifespan.

#2 Plastic sheets

One of the cheaper, more readily available options for a weed barrier is plastic sheeting. It’s effective at reducing weeds because it is huge and covers a lot of ground in one go, so you don’t have to worry about weeds growing through uncovered areas.

The disadvantage, however, is that plastic is not environmentally friendly and, in some cases, not as aesthetically pleasing as landscape fabric. Sometimes, you’ll find that the corners of the plastic will stick up through the rocks and ruin the look you had planned for your garden. Plastic also tears easily and does not decompose quickly. It can be heavy and difficult to remove and dispose of, if you choose to remodel your garden after a few years.

Plastic is also not easily permeable. As a result, the rain will not sink into your soil but instead water will flow out to the sides and could flood the rest of your garden. Your plants may suffer from this, if they can’t tolerate high amounts of water at once.

Plastic might also suffocate other living organisms in your soil, eventually leading to the roots of your plants rotting.

If you want to go with plastic for now, however, you can cut holes through so that the air and water can reach your soil. If you can, try getting plastic with UV protection so it doesn’t break down easily.