Mulching Orders by Carol Klein*
After the recent deluges, it might be deemed untimely to talk about water conservation in the garden. But despite disastrous events, sooner or later we all need to employ any means possible not to have to rely on hosepipes and watering cans. One way to do this is cover your soil with a mulch.
Mulching isn't new - top-dressing with old muck or home-made compost has always been a valuable practice - but the aim here is to feed the soil and the plants growing in it, and while the resultant humus-rich soil retains more moisture, feeding plants individually does not afford some of the other benefits that overall mulching provides.
This latter approach is a fairly recent innovation, and there is now a bewildering array of products available. Some are organic and in various states of natural decay; others are inorganic and unchanging. Chipped bark is the most popular, but it deprives the soil of nutrients as it rots down; grass mowings usually form an anaerobic mat and are best avoided, too; rough compost, seaweed, bracken, sheep's wool and even old natural carpet or cardboard have their aficionados.
Then there are gravel, shingles, pebbles, even quarry waste and "scalpings".
Whatever you use, the aim is to restrict evaporation. A thick covering also acts as insulation and helps moderate soil temperatures, so there is less likelihood of soil freezing in winter or frazzling in summer. Mulch also protects the surface of the soil from erosion by both wind and rain, and as a weed suppressant, it is second to none.
*Extracts taken from Carol Klein's article which appeared in The Guardian colour supplement, 21 July 2007