Why?
During cold or dry times plants become very vulnerable. Mulching can offer huge benefits in these situations. It has the ability to lock in moisture and to insulate roots from cold in addition to offering protection against weeds and providing extra nutrients for a plant. It also has the added benefit of making the tops of pots and borders more aesthetically pleasing.
What?
Mulch can be made from a number of substances, usually from organic materials but there are some exceptions. Examples of organic mulches include leaves, grass clippings, woodchip, straw, peat moss and cardboard. The mulch applied may also be either permanent or temporary. Inorganic may include rubber or plastic mulch. When considering the type of mulch to use, many factors will play a role. Factors to take into consideration are the cost, availability, appearance, cleanliness and its effect on the soil (pH, decomposition, combustibility).
How?
The process of mulching itself is relatively simple. Preparation is key: firstly the site must be as clear as possible. This includes weeds in particular, as they can be difficult to remove once the mulch has been applied and existing weeds will compete with the plants for the benefit of the mulch. Secondly, make sure that the soil in the area to be mulched is moist. If necessary be sure to water the area. It is important to carry out this step as once a layer of mulch has been applied it can be very difficult to sufficiently wet any dry soil. To apply the mulch itself first fill up a wheelbarrow or similar container with your mulch of choice. Then proceed to spread a layer of mulch around the plants or across the area of soil, a spade can be used to spread it. The layer should ideally be about 5 cm (2 inches) thick. When spreading around plants you should always leave a small gap around the stems. A rake can then be used to achieve a levelled finish.
When?
The optimum time of year to apply mulch is dependent on the effect you are trying to achieve by the application of mulch. If aiming to protect the roots and crowns of newly planted trees, shrubs or herbs from frost, the best time to apply is the autumn or early winter. However, in order to protect entire beds or borders from quickly drying out in the summer heat, the mulch should be applied in late winter or early spring in order to trap in moisture created from wet weather.