Improving your soil
Unfortunately we are not all blessed with perfect, rich, loamy soil in our gardens. Clay soils can provide a good, fertile medium for growing as they retain moisture and nutrients, however they will become waterlogged and unworkable when wet. Sandy soils are the opposite and require improvement to assist with moisture and nutrient retention.
By regularly working in a soil improver, these problem soils will gradually improve over time in terms of structure and fertility. Improving your soil will also replenish nutrients, important for plant growth and as a result, plants will be more resistant to diseases, pests and adverse weather conditions.
When to improve your soil
Soil can be improved at any time of year, however your soil type and what you are growing will determine the best time.
Empty flower or vegetable beds can be improved at the same time as digging over in late autumn or winter, providing the soil isn't too wet. With heavier, clay soils it may be necessary to wait until late March or April.
Avoid digging or walking on the soil when wet, as this will damage the soil structure further. Working off boards will help prevent this.
How to improve your soil
Unplanted areas should be thoroughly dug over to relieve compaction. With good, well-cultivated soils a light forking over will suffice most years. Clay soils can often have a layer of solid clay underneath the top layer. If this is the case, double digging will be necessary to break this up and prevent a 'panning' effect which will hinder drainage.
If conditions allow, clay soils can be dug over in late autumn and left over winter. The frosts will break down large lumps making the soil much more friable in spring.
Spread a thick layer of organic matter over the surface and dig over again using a fork to work it into the surface to a depth of about 200mm.
For clay soils we recommend a layer of soil improver about 75mm deep. Sandy soils require about 30mm, and thin, chalky soils need about 50mm of organic matter adding each year.
Areas which are planted can be lightly forked over, if it's possible to do so without damaging plant roots. Spread a layer of organic matter over the surface around the plants. Over time it will naturally break down and be worked into the soil by worms and improve the soil beneath. Take care not to smother plants or put the mulch too close to plants which could cause them to rot.
It is recommended gloves should be worn when using soil improvers, and hands washed after use.
What to use as a soil improver
A variety of different materials can be used as soil improvers (also known as soil conditioners):
Natural, peat free soil improvers such as Rolawn Soil Improver
Manure should be well-rotted for at least a year, otherwise it will release nitrogen into the soil too quickly, which can be damaging to some plants.
Compost can be made from garden waste, grass cuttings, shredded newspaper and kitchen waste.
Leaf mould also makes an excellent soil improver and makes good use of leaves cleared from the lawn, however nutrient levels are quite low.