How to improve your soil
Late winter and early spring, when the garden is quiet and beds are relatively empty, is a great time to improve your soil. Good soil quality is essential for healthy plant growth, reduces pest and disease problems and will lead to strong, productive plants later in the year and digging over your beds each year will help to loosen any compacted areas, get rid of weeds and is the perfect time to add organic matter, green manures or fertilisers. The addition of organic matter in particular, every couple of years, whatever your soil type, will really help to improve your soil, improving drainage and aeration in heavier soils and helping to conserve moisture on lighter, sandier ones.
Organic matter, such as home-made garden compost, leaf mould or well rotted animal manure improves your soil twofold – not only does it increase soil fertility, it also improves soil quality by improving the soil structure. This makes plant roots able to access nutrients more easily and also makes soils able to hold on to nutrients much better. Organic matter can be added by applying a 5cm layer onto the surface of the soil. This is either dug in with a fork or left on the surface as an organic mulch to suppress weeds and conserve moisture and will eventually be taken down into the soil by the worms.
Shop bought fertilisers can also be dug into bare soil but have a shorter-term effect and will only effect soil quality by improving fertility; they have no effect on structure. If soil structure is poor, as can be the case with sandy or very heavy clay soils, nutrients can be easily leached away and lost through the soil, or plant roots can find it hard to move through the soil and access them. Adding bulky organic matter however, provides something to hold moisture and nutrients in sandy soil and breaks up the large, heavy particles in clay soil, helping it to drain better and making it easier to dig.
A great alternative to organic matter is to use a green manure. These are fast growing crops that are sown into empty beds purely for the purpose of improving soil quality - they are dug into the soil to improve fertility and structure and are ideal wherever an area of ground is to be left bare for six weeks or more. Once sown they will 'mop up' any nutrients already present in the soil, preventing them from being washed away by the rain, and when dug in will break down and improve soil quality by releasing nutrients. They can be sown in autumn and late winter and are dug in when leafy and lush, just before flowering.
Whichever you choose, remember that good soil quality and going to lengths to improve the quality of your soil now, is essential for the production of strong, healthy, high yielding plants throughout the year.