Mulch

by: Chris Moorhouse

What is mulch anyway? Mulch is a layer of organic material such as compost or well-rotted manure, peat, bark, grass mowings or other similar material. A common mistake is to use un-rotted or fresh material; this is a bad thing. If this material is leafy it will attract garden pests like slugs and sails and as it rots it uses up much of the nitrogen in the soil robbing the plant of its food. It also looks untidy. A well-mulched garden looks as if it has been dug recently.

Mulch has a number of functions:

It stops roots from drying out.
It keeps weeds down.
It keeps frost off the roots in winter and keeps them cool in summer.
It feeds the plant when it rots into the soil.

When to apply.
When you apply mulch depends on the reason you are using it. Always apply mulch when the soil conditions are good. If you are using it to protect your bulbs from a winter freeze, you need to mulch in autumn (fall), before the soil gets too cold. If you have had a long cold winter and your bulbs are slow coming out in spring remove the mulch to let the sun warm the soil.

In the summer, you would use mulch to stop the soil from drying out from too much sunshine. As above, use mulch when conditions are good i.e. when the soil is moist. If the soil is too dry and you do not get rain heavy enough to penetrate the mulch within a short time, your plant's roots may dry out. If you must mulch in dry conditions make sure to water well before you do. The soil should also be warm. Do not apply too early in spring when the soil is too cold. If you do, the mulch will slow down the warming of the soil by blocking the sun and your plants may not do well.

Many people are today using black polythene sheets and other artificial mulches. They do perform most of the functions above but I have to say that I never use them myself as I feel that they ruin the look of the garden. In addition, they will not rot down and provide the vital organic contribution that natural organic mulches do.

Usually a three to four inch layer of mulch will do. However, care must be taken that the mulch is not in contact with the plant stem. There are two reasons for this. First, if you frequently get a breeze blowing the plant enough to rattle it around the friction will damage its skin and allow infection in. Secondly, if the stem is damaged or delicate some if the bacteria rotting your mulch may invade the plant and slow its growth. Most plants will resist these infections but why take a chance. Just keep the mulch back an inch or two from the stem.

Mulch can sometimes be a bit smelly. Don't let this stop you using this very beneficial gardening technique. The smell seldom stays for more than a few days and the benefits to your plants are obvious.