You can put wood mulch straight over rocks in your garden. Removing rocks can be expensive so put wood mulch over the top without removing rocks to save money, prevent weeds, and improve your soil. Apply wood mulch 1-2 inches thick to cover rocks and provide a fresh, new look in your garden.
How to put wood mulch over rocks – Tips
When you cover landscaping rocks with wood mulch you can create a completely new look in your garden. Cover the rocks with at least 1-2 inches of wood mulch to completely hide the rocks and to fill the cracks between them.
The best mulch to choose for this is a mixed tree or bark mulch. A mixed tree mulch will contain a range of piece sizes, from small to large which will fill the gaps between the rocks. This will stop the weeds from growing through.
How to cover landscaping rocks with wood mulch
To cover landscaping rocks with wood mulch, first remove the larger weeds that are poking through the rocks. Wear gardening gloves and gently pull them out trying not to disturb the rocks. Any dirt that is pulled through to the top of the rocks will encourage more weed growth.
Use a rake to flatten the rocks A flat surface of rocks will mean that the wood mulch will sit flatter. Pour the wood mulch on top of the rocks, flattening it over with a rake. Make sure you keep it around 2 inches thick.
Adding 1-2 inches of mulch will block the light reaching the soil and stop the weeds from growing. If weeds do grow through, they will be easier to pull out as they would have had to work harder to grow through the mulch. I rarely get weeds growing through the mulch at home.
Landscaping rocks vs wood mulch
Wood mulch is better than landscaping rocks for preventing weed growth, it helps to improve the soil underneath and will keep moisture in your soil for longer. If wood mulch is laid 1-2 inches deep it will prevent weeds without using weed matting.
Wood mulch will benefit the soil underneath the rocks over time, improving the soil to make it better for planting. Adding wood mulch to the top of rocks will encourage microbes to break down the organic matter and improve the soil. This will attract worms which will eat the microbes and make micronutrients available for plants.
Landscaping rocks can be a low maintenance way of mulching between pavers or stepping stones and can be great if you don’t intend on planting anything in between. I prefer natural wood mulch as it stops weeds and improves the soil underneath at the same time.
Putting down weed mat before laying mulch
When I laid bark mulch over rocks I did not lay weed matting. Previously weed matting was laid underneath the rocks and weeds were still growing through. Weeds will grow through the cracks between the weed matting and pavers or through the weed matting as it starts to break down.
If you lay mulch at least 1-2 inches thick, this will be enough to stop most weeds without using weed matting.
Wood mulch over landscaping rocks is good for plants
Both landscaping rocks and wood mulch offer benefits to plants as they will hold moisture in the soil and stop some weeds. If you lay wood mulch over landscaping rocks you will get the added benefit of greater water holding capacity as the wood chips absorb and release water.
Mulch will keep the area under your plants cooler than landscaping rocks which can heat up and radiate heat. Heat sensitive plants can burn more easily on hot days with landscaping rocks.
I have also used landscaping rocks and mulch together to build up soil around my star jasmine and then cover with a sugar cane mulch to keep the water in. The landscaping rocks help to keep the soil raised around the star jasmine to improve drainage, and the sugar cane mulch helps to improve the soil by adding organic matter and keep the moisture in.
Laying wood mulch over landscaping rocks at home
We have recently bought our townhouse and the whole side and front of the house was covered in landscaping rocks. After 2 months they rocks were completely overtaken by weeds which were difficult to pull out.
The rocks had been laid around 5 years before, over weed matting and the weeds were still growing through quickly. I had assumed that the previous owners had kept the weeds under control by spraying with pesticides as it seemed the only way to keep on top of them.
Over the years it seems that soil had gathered around the rocks providing a great place for weeds to grow. I also have a dog that likes to use that side of the house a his bathroom and the rocks made it incredibly difficult to pick up dog poo. I made the decision to add bark mulch instead of the rocks, moving the rocks to one side and filling the gaps between the pavers with bark mulch. What remained was piles of rocks on the edge of my pavers.
I didn’t want to pay to have rocks removed and sent to landfill so I simply covered them with mulch. This hid the rocks and stopped the weeds from growing through. This was a simple way to refresh the space, stop the weeds and make it easier to pick up dog poo. The wood mulch also soaks up dog wee better too making the side of our house much cleaner.
For more on mulch, check out the article below.
I am an accredited practicing dietitian, experienced gardener and a dedicated cook. I love writing and sharing my experience so you can learn from my successes and mistakes.