A Guide to Mulches

Retaining the soil health and retaining moisture is key to a healthy and productive garden. To this end, using mulches of various kinds can be a good way to ensure that your garden is the very best it can be, both in terms of its function and its appearance. There are various different options when it comes to mulch, all of which may be the best thing to choose in certain circumstances. Here is a brief guide to the various sorts of mulch and how to use them:

Living Mulches/ Green Manures:

Quick growing plants can be grown to provide ground cover and suppress weeds. These can then dug in or chopped and dropped at the end of the growing season to add fertility to the soil. Common green manures include mustard, clover, alfalfa, rye or winter field bean.

Organic, biodegradable Mulches:

Other organic biomass can be left on the soil surface to act as a mulch. These will degrade over time and must be replenished but they will add necessary fertility to the soil of your garden. Apply specific mulches according to the needs of the plants you wish to feed. Mulch in the UK is best applied in spring and lifted in the late autumn. Lift mulches in extremely wet weather or they can encourage slugs and snails. These biodegrdable mulches will not repel weeds effectively but can retain moisture for roots in the summer and retain or improve soil health. Here are some examples of good biodegradable mulches:

Grass clippings:

Grass clippings are often an abundant commodity in the garden. They are extremely high in nitrogen and though they rot down quickly, can provide a sufficient barrier to retain moisture in the summer. Use around leafy vegetables, for example, as they need lots of nitrogen for leaf growth.

Comfrey leaves:

Comfrey is a miracle plant for the fertility of your garden. Chop and drop comfrey leaves as a mulch and allow them to break down to feed the plants with their excellent mix of nutrients which the comfrey plants are able to collect from deep in the soil with their deep tap roots.

Leaf litter/ leaf mould:

Forests are the most successful ecosystem on our planet. Nature knows best and allowing leaf litter to form in your garden beds can mimic nature, working with it rather than against it.

Garden compost:

Spread garden compost liberally around your garden to ensure your soil remains healthy and nutrient rich.

Well-rotted manure:

Well-rotted manure, like compost, contains a balance of good nutrients for healthy plants and good yield from fruit and vegetable crops.

Bark or wood chip:

Bark or wood chip takes longer to break down and you should bear in mind that as it rots down it will take some nitrogen from the soil in the short term, so could be better for paths than for beds. That said, this can be an effective mulch to spread on areas where you want to retain lots of moisture or where you want to suppress weeds. It does break down over time and will eventually have to be renewed.

Non-biodegradable Mulches:

For a low-maintenance garden or for paths, non-biodegradable mulches could be the best choice.

Sheet mulch:

Permeable plastic or composite material fabrics can stop weeds entirely, though look ugly and are not necessarily the most environmentally friendly choice. Though unappealing to look at, they can be disguised with bark or other materials over the top.

Gravel:

In a low maintenance garden or just on paths, you may wish to have a ground cover that will remain. Gravel is one option, as are sea shells, glass aggregate and other decorative ground covers. 

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