Barks and mulches serve many purposes, with the benefits reaching far beyond their immediate surroundings. Not just a decorative finish to a border or a weed suppressant, a covering of bark or mulch has a protective and restorative function for both plant health and the environment.
What’s more, it’s a great investment for the future. A small amount of effort and outlay now will save time and money in the long-run, reducing the need to weed and water as well as the need to replace lost plants.
Extend plant life
One of the protective functions of bark or mulch is helping to regulate the soil’s temperature and protect plants against extremes.
A 50-75mm layer of bark or mulch applied to beds, borders and pots acts as an insulator. It will help to protect plant roots by locking in beneficial residual ground warmth so should be applied before heavy frosts reduce the soil temperature.
In warmer periods, a layer of bark or mulch will prevent plants from suffering due to moisture loss.
In both cases, plant loss is reduced which means your initial outlay, be that time or money, is saved and no further investment is needed to replace them.
Left to their own devices, organic matter from trees and plants would form a layer on the surface of the ground, which gradually rots down into the earth. As a result, the structure of the soil is improved and plant health is boosted as nutrients and other essential elements are reintroduced.
You can achieve the same outcome by digging in some mulches. In fact, in areas of heavy shade, where plants are struggling to grow, it is advisable to use a mulch to enhance the fertility of soil.
Reduce water use
With the need to reduce water usage becoming ever more important, applying a layer of mulch is a quick win.
Mulch helps to retain moisture within the soil by preventing evaporation. It also suppresses weeds, which compete with your plants for any available moisture. Using mulch and bark in your garden will help to reduce evaporation by up to 75%. (Source waterwise.org.uk)
Mulches not only reduce evaporation, but depending on your choice of material, can also increase the amount of moisture your soil is able to hold. A soil improver applied as a mulch will also, over time, be worked into the soil by earthworms, improving the soil structure.
Alleviate flooding and soil erosion
Mulches also help prevent problems associated with water run-off during heavy rain. Often, when water is scarce in summer, thunderstorms bring very welcome rain. However, this can run off rapidly resulting in flash flooding, causing more harm than good for plants and soil structure. A mulch helps to slow the movement of water, allowing it to percolate into the soil where it can be taken up by plants’ roots and help reduce the risk of flooding.
Help suppress weeds
Weed control is another benefit to be gained from mulching. When bark or mulch is used to cover exposed areas of topsoil, weeds will have less access to light and oxygen, suppressing their growth and helping to save time on garden maintenance.
Enhance the appearance of your garden
The natural colour of barks and mulches means they easily improve the look of any garden, helping to elevate the visual impact of flowers and foliage while complementing the surroundings.
For paths and walkways, a wood chip or bark mulch provides a relatively cheap and easy alternative to stone, as long as a suitable weed suppressing membrane is used underneath.
Improve safety in play areas
Certain barks are suitable for use as a protective surface in children’s play areas but must be independently tested in accordance with BS EN 1177:2018 Impact Attenuating Playground Surfacing - Determination of Critical Fall Height.
Safe and responsible bark and mulch products
As well as caring for your local ecosystem, you can help to further protect the wider environment by choosing sustainable products that are responsibly sourced. It’s also a good idea to check that the barks and mulches you choose are free from chemical contaminants and that they are suitable for use where you are intending to apply them. For example, pH levels can vary and may not be suitable for all plants.
You’ll find more advice on how to use mulch in our step-by-step guide.