Keeping mulch in place is essential for creating a neat and attractive garden. Mulch not only enriches soil health but also protects plants from extreme weather conditions. But if you’re not careful, it can easily be washed away by heavy rainfall or irrigation systems.
The Type Of Mulch Influences Its ‘Floatability’ Factor
The type of mulch you use can influence its potential for floating away in water.
Two factors heavily influence how likely it is for your mulch to float away during heavy rain: Weight and ‘Stickability’.
In other words; mulch that is heavier and clings to itself is more likely to stay put.
Wood chips and chunks of bark for example are known to float away during a heavy spell of rain. This is because they don’t stick that well together. Buying larger and subsequently heavier particles of this mulch will help prevent them from being displaced.
Finer mulches such as compost, straw, and leaf litter are less prone to washing away since they easily cling together.
7 Ways To Keep Mulch From Washing Away
1. Create A Barrier

Creating a barrier from rocks, bricks, stone, or other materials around the perimeter of your garden will help contain the mulch and keep it from washing away.
You can even build a shallow trench that is a few inches deep around your garden. This will catch the mulch, allow you to simply rake it back in.
Creating a perimeter with plants can also make a suitable barrier. Planting a line of shrubs or low-growing trees along the edge of the mulch bed can help keep it in place. The roots of these plants will help anchor the soil and make sure that your mulch stays put. Suitable plants include shrubs such as juniper and rosemary, or low-growing trees like boxwood and holly.
Lastly, you can use mulch itself to create a barrier. Ensure the mulch is deeper and more compact towards the edge of the flower bed.
2. Use A Different Type Of Mulch
As we explained before, the type of mulch you use will affect how easily it will float away.
Ideally, you want mulches that stick together. Shredded mulch is great as it will tangle into itself, preventing it from moving.
Heavier mulches are also ideal. Hardwood mulches are heavier than softwood types (such as pine) and so will be better equipped to remain static during water movement.
3. Add More Mulch
You can add more mulch in thin layers on top of the existing mulch. Ensure to water each layer down to help it become more compact. This higher density will work well to keep the mulch in place during rainy days.
4. Remove Landscape Fabric
Whilst landscape fabric is great at preventing weed growth used to prevent weed growth, it also provides a smooth surface for mulch to slide on. This is especially prevalent if the mulch lays on a decline.
You can instead remove the fabric/sheet and apply extra mulch to increase its weed-stopping abilities.
5. Use A Mulch Adhesive
If you really want to take matters into your own hands, you can use a mulch adhesive that bonds mulch parts together.
Most of these products will take maximum effect within 48 hours and can last up to a year or more.
6. Reduce The Slope
Naturally, the more sloped your garden is the higher chance your mulch will become washed out. Running water will become more powerful the more declined the slope is.
To make gravity work in your favor, you can terrace sections of your garden to break up the slope as much as you can.
7. Improve Drainage

A fantastic way of reducing mulch erosion is to improve the drainage of your garden bed. This can be done in several ways:
- You install pipes in trenches in and around the garden bed. This is known as a French drain, and will effectively divert water away from your mulch.
- Amend the soil. Adding organic matter such as peat moss or compost can help improve the soil structure, allowing for better drainage and reducing erosion.
- Use plants with large root systems. Specific plants are great for stabilizing soils because of their dense root systems that act as anchors against erosion forces like wind and rain. These plants also increase water infiltration into the soil, reducing runoff and helping minimize erosion. Such plants include Daylily, Globeflower, and Primrose.
- Create berms or swales in your landscape design. Berms are raised mounds that help direct water away from your garden bed and toward the drainage system. Swales are shallow ditches that provide a gentle slope for water to flow away from garden beds. Both help reduce runoff, leading to less erosion and better water infiltration into the soil.
How To Keep Mulch In Place Without Edging?
Keeping mulch in place without edging is a common question that we’ve seen a lot of people ask. The reason some people do not want to use edging may vary, from not wanting the added expense, to preferring a more natural look in their garden that is not compartmentalized.
Methods 2 through 7 we’ve mentioned previously are effective methods of keeping mulch in place without edging. To reiterate, this includes using denser mulch or mulch that better sticks together. Use a mulch adhesive, and landscape terracing to reduce slopes and improve the drainage in your garden to help mulch stay in place.
Another trick is to use plants and even trees to create wind barriers that will stop wind from blowing away your mulch and garden bed. This looks natural and will not look as artificial as other edging solutions.