The magic of mulching!

Adding a layer of organic mulch to your beds and borders such as compost or manure can do wonders for your garden

Mulching is one of the most important things you’ll ever do in your garden. So, what is it and why do we do it?

Put simply, a mulch is any layer of material applied to the surface of the soil and mulching is the act of applying it. A mulch can be either organic such as manure, compost, leaf mould or bark or it can be inorganic such as stones, gravel, pebbles, or chippings. The main benefit of mulching is to reduce evaporation from the soil surface and help conserve moisture for your growing plants, so they don’t get stressed. This is especially important as Climate change may lead to challenging growing conditions with less rainfall in some areas. It also insulates the soil, giving it a nice warm blanket in the winter but also allowing it to stay cool in the summer. It also reduces soil erosion by wind and rain and helps keep away the weeds. All these things will help improve the health of your soil and plants.

Whereas inorganic mulches can be decorative and do contribute to overall plant health, organic mulches can do the same thing but offer so much more.

Examples of inorganic mulches:

·         Crushed stone / slate

·         Gravel

·         Cotswold stone chippings

·         Pebbles

Examples of organic mulches:

·         Farmyard manure – especially horse manure

·         Garden compost

·         Mushroom compost

·         Composted green waste (from council green bin collections)

·         Worm compost

·         Leaf mould – ideally oak, hornbeam or beech leaves - left to rot down

·         Composted bark chippings – especially good for woodland plantings

·         Grass chippings

·         Pine straw – great for acid-loving plants

Not surprisingly organic mulches, such as your own garden compost, bark chippings, farmyard manure or leaf mould contain the magic ingredient organic matter. Organic matter is a catch all term for biological material from living organisms, anything that is or was alive. Basically, dead plant material. If it is highly decomposed into small particles it is known as humus and is dark in colour, that’s what gives healthy soil its characteristic brown earthy colour. Adding things like manure, rich in organic matter, whether it’s added to the surface as a mulch layer or dug in and incorporated into the soil directly, can greatly increase the fertility of the soi and help it to retain large volumes of water. This is particularly important in the summer months, especially if it turns dry. It also improves overall soil structure, especially on sandy soils.

Organic mulches also promote healthy soil organism populations, macro-organisms such as earthworms and micro-organisms such as nitrogen fixing bacteria and beneficial mycorrhizal fungi.

Adding a layer of compost to the surface of your soil will improve it.

Using organic mulches will also add to the nutrients of the soil whereas inorganic mulches such as gravel won’t. The exact nutrient levels depend on the mulch. Nutrient levels are higher in garden compost than leaf mould. When mulches are applied for their nutrients, they are best applied from late winter when soil is moist and warm, and the plants are growing.

Most organic mulches are sustainable, they come from renewable natural sources, they aren’t mined, processed, and transported great distances unlike some mineral mulches.  On the over hand they can be variable and can contain weed seeds if the material hasn’t been composted properly so be aware of what you are applying especially if you don’t know where it’s come from.

Points to remember when mulching.

·         It is always best practice to apply mulch after its rained or when the soil is wet. This way you lock in the moisture for the plant to use over the growing season. If the soil is dry, wet it first. Water doesn’t easily penetrate the mulch once its down.

·         Keep the mulch away from the stems of the plant. You don’t want moisture building up against the bark as this could encourage rotting or disease build up.

·         Make sure you mulch to a depth of 10cm. If you are using a mulch for weed control, any less than this is completely pointless.

On top of this they can also be highly decorative and improve the visual appearance of your beds and borders. A nice layer of ornamental bark chippings looks fantastic on shrubs borders.

I’m a big advocate for using mulches, especially organic ones; mulching saves water, suppresses weeds, improves the soil around your plants and makes for a nice and tidy looking garden. So, what’s stopping you!

Benefits of organic mulches summary:

·         Reduce evaporation from the soil surface, conserving water

·         Insulating soil keeping it warm in the winter, cool in summer

·         Protect the roots of trees in the winter

·         Add nutrients

·         Keep down weeds

·         Reduce soil erosion

·         Promotes increased healthy soil organism populations

·         Makes your garden look pretty.