Soil recipes
Recipes for Soil Composts
Plants generally obtain the nutrients they need from the soil in which they grow and different plants have different needs.In our gardens we may have acid or alkaline soil, with many variations between the two extremes. Soil is made up of differing percentages of a variety of ingredients. Much work has been carried out to discover the best mix for each variety of plant and also for the same plant grown for different purposes. For example the needs of grass grown for a shady lawn and for a cricket pitch or golf course will be very different.
Some soil examples
A good general purpose soil compost will consist of half good garden loam, one quarter sand and one quarter humus i.e. leafmould, garden compost or peat-substitute. Please do not use organic peat: there are a number of equally good substitutes (such as coir) which will not cause ecological damage to our precious wetland areas. A small amount of bonemeal would also be beneficial.For germinating seeds the main need is for a basic growing medium, the nutrients being provided by the seed. As the seedling grows, it needs a gradually increasing amount of nutrient, so it is usually pricked out and transferred to a slightly richer compost (at the same time giving each seedling more space in which to develop). There are a number of commercially-available composts designed for this purpose.
More specialist needs
Some types of plant have very specific needs which are not easily available in regular garden soil. These are best catered for by making up special composts yourself or by buying ready-prepared ones.Cacti are a good example. They need particularly good drainage, being used to extremes of desert soil. Thus a compost for them will need a higher proportion of material which drains well. A suitable mix might consist of equal amounts of loam and sand, with a half-portion of humus. Perlite is sometimes used in commercial compost to aid drainage as well as fine gravel.
Fine-rooted plants such as many houseplants (e.g. African violets, ferns, begonias) need equal parts of loam humus and sand, and will also benefit from a small quantity of manure, which can be bought pelleted. As above, perlite may be used to aid drainage.
Acid-loving plants such as heathers, azaleas and rhododendrons will thrive only with a high pH compost or soil. For these equal parts of loam, sand and peat-substitute, together with a half-quantity of garden compost or leafmould is appropriate.
Grass for cricket pitches and golf courses need highly-efficient drainage, and quantities of sand are blended with the soil to improve both drainage and compaction.