Mulching, why and when?
The practice of covering the soil around plants with vegetable matter or other material, organic or inorganic, is carried out for a number of reasons including to conserve moisture and to help roots to maintain an even temperature.
Another purpose is to improve the fertility of the soil with garden compost or well rotted manure. The third reason is to smother emerging weeds. In addition, mulching attracts centipedes which prey upon many garden pests.
Although mulching can be carried out at any time of the year, it does most good in late spring when the ground has been warmed by the sun but still holds winter moisture and when weeds are yet to become established.
Fork or hoe the ground just before spreading the mulch. Without doubt this is one of the most important tasks carried out in the gardener’s year. It isn’t just about spreading anything that comes to hard, it’s about choosing the right mulch for the right plants.
Animal manure, when well rotted, will mingle with the soil and enrich it. Even before it has entirely rotted down, although not when it is raw, it makes fine mulch. It should be stacked for at least three months before being used.
Bark, when it is ground to a finer texture, is an ideal mulch. Pleasing to look at and extremely durable. Bark keeps weeds at bay and eventually, when it breaks down, adds humus to the soil without compacting it. However, as it contains no nutrients whatsoever, plants surrounded by bark will need feeding.
Black polythene warms the ground and suppresses weeds in flower and vegetable beds.
Do not forget that it must be fastened down around the edges with bricks or pegs or by burying in the soil. Garden compost which is composed of grass cuttings, deadheaded flowers, exhausted bedding plants, weeds and kitchen waste which has been collected and stacked over several months makes a superb mulch but be careful that the components have not been treated with herbicides.
Adding a sprinkling of dried blood or any other high nitrogen fertiliser between each eight inch (20cm) layer of waste will hasten the rotting down process.
When commercial mushroom growers have harvested the crop they sell the compost in which it has grown which makes excellent mulch for lime loving flowers and vegetables, as does the compost from grow bags which have been used for tomato growing.
Stones, pebbles and gravel are not only decorative when spread around tree trunks or potted plants but also help to retain moisture, especially highly effective if perforated black polythene sheeting is stretched beneath it to allow drainage.