Improving Soil Fertility by Mulching
It is widely recognized that mulching with organic materials improvesfertility. ‘Feed the soil, not the plants’ is the motto of the ‘organic’ school, and one of the key methods of doing so is by mulching. It is perfectly feasible, and very effective, to cover the soil with a mulch 10-15cm (4-6in) deep using materials such as , well-rotted manure or seaweed. Any mulch which has not been worked into the soil by worms during the course of the season (and it is astonishing how it disappears), can be dug in at the end of the year. Where you use a thick mulch, planting is generally done through the mulch. If necessary, however, the mulch can be scraped to one side to enable seed to be sown in the soil.
Transparent plastic mulches are very useful for warming up the soil in spring, enabling sowings to be made earlier. Seeds of strong plants, such as , pumpkins and beans, can be covered with a strip of plastic after sowing, and as soon as the are visible, a slit can be cut and the young plants eased through. The plastic mulch encourages germination by keeping the soil moist.
Perforated transparent films can be laid over the soil after the crop is sown or planted, and because of the numerous perforations in the film they stretch, virtually growing with the crop. After a certain period, which varies with the crop, they have to be removed; but by this time the crop has been given a very good start in life, and is well ahead of any sowings made completely in the open.
Protection Against Frost
A thick blanket of organic material goes a long way towards preventing frost from penetrating the soil. It is particularly useful where root vegetables such as Jerusalem artichokes, carrots, swedes,and are being left in the soil during the winter. If the ground is frozen solid, lifting is normally impossible; but a mulch provides just enough protection to make it feasible.
In a garden without cloches, a light mulch of bracken or straw can be used to protect over-wintering greens such as, chard, winter , lamb’s lettuce, endives and from very heavy frost. If possible, the mulch should be laid over sticks or low wire hoops, trapping a layer of insulating air beneath it and preventing it from lying too heavily on the plant leaves. It should be removed if the weather turns mild or wet; otherwise it becomes soggy, encouraging slugs and making plants rot.