Mulching your garden: how and why to mulch

Martyn Cox ( 04 March 2016 )

Find out how mulching your garden can prevent weeds growing and improve your soil at the same time.

If you want to spend your summer relaxing in the garden, rather than weeding and watering, try mulching beds and borders - a thick layer of leafmould, composted bark or other covering material, will make maintaining borders easy and give your plants a boost at the same time.

Why mulch?

There are many reasons why mulching the soil every year is a good idea. A deep mulch will prevent weeds from growing, which rob moisture from the soil and need constant hoeing or pulling out by hand to control. Although some weed seeds will germinate on top of the mulch, they cannot anchor themselves well in the bulky material and are easy to uproot.

Although winter rain can wash goodness out of the soil, you can give it a pick-me-up by spreading mulch, because as the material rots down nutrients are released back into the earth. If applied over wet ground in the spring, it will also help to lock in moisture that can be used by plants in warmer weather. This is a real boon given recent water shortages and the threat of hosepipe bans.

Mulches can also be spread over tender bulbs or around the stems of less hardy plants in winter to help insulate them from frost.

Related: how to improve your soil.

Which mulch?

If you have made your own leafmould or garden compost, this is ideal, but don't worry if you haven't. Garden centres and DIY stores stock a large range of materials that can be used instead, including well-rotted farmyard manure, composted bark and organic wheat straw.

Choose a mulch that will suit your garden - wheat straw sets off tropical plants wonderfully, but looks out of place in a traditional border. Probably the most popular material is bark, which is available in several grades. As a rule of thumb: the finer the grade, the quicker it will rot down and need replacing.

In some gardens gravel or slate shingle makes an attractive mulch - lay it on top of a sheet of landscaping fabric (available from garden centres) to prevent it from being trodden into the soil.

Related: how to make a compost heap.

How to use?

Before laying a mulch, clear the site of weeds and make sure the soil is moist. 

If necessary, soak well as it will be difficult to wet the soil after it has been laid. Spread a 10cm (4in) layer of material across the whole area with a spade and rake to leave a level finish - wear gloves if you are handling manure or composted straw. 

Although the mulch will help to conserve moisture, you will have to apply water during prolonged spells of dry weather.

Related: gardening in waterlogged soil.

The opinions expressed are those of the author and are not held by Saga unless specifically stated.

The material is for general information only and does not constitute investment, tax, legal, medical or other form of advice. You should not rely on this information to make (or refrain from making) any decisions. Always obtain independent, professional advice for your own particular situation.