Mulch is generally used to improve the quality of your garden soil, but it has many other benefits. It adds nutrients, smothers weeds and helps retain moisture. It stops soil drying out in summer, and keeps warmth in the soil over winter, protecting plant roots and tubers from frost.
What is mulch?
Mulch just means any material that you apply over the soil surface. It is often biodegradable like compost or bark chippings, which breaks down gradually to release nutrients into the soil below. But it can also include permanent weed-suppressants like gravel and slate.
Which mulch to use
For flower beds and borders, use a biodegradable mulch. Well-rotted manure and garden compost are good choices, and also work well around fruit and vegetable plants.
Bark and wood chippings are popular for beds because they look good too. You can buy different grades, depending on the size of the chippings. Smaller chippings will rot down faster.
I like composted bark which has already started to rot down. It looks more natural than pure bark chips.
You can also use leaf mould or spent mushroom compost. If you grow strawberries, add a mulch of straw around the base of the plants.
How to mulch beds and borders
You can apply mulch to new and established beds. First, prepare the soil by removing a
ny weeds. Water the soil if it is dry – it’s more difficult to water plants through mulch.
Now apply a thick layer of mulch across the entire soil surface, spreading with a rake or trowel. The layer should be 5 to 7cm thick. Take care not to smother young or low-growing plants.
Single trees or specimen shrubs should be mulched to about the radius of the canopy. Avoid the mulch coming in direct contact with the stem.
Bear in mind that you may need to water plants more than usual to get moisture to the roots – you have effectively made the soil deeper.
If you want to mulch a rock garden, remove the weeds and water the soil as before, then apply a layer of gravel around the plants. It should be about 2 to 4cm deep.
Only reapply mulch when it has completely rotted down.