Digging
All digging is properly done with a spade, the blade of which is, on average about 25cm long. This is the length referred to when digging “one spit deep” is recommended.
Digging is done to get air into the soil, to get the lower layers weathered, to help excess rain drain through and to mix in plant foods and materials to improve structure with mostly rotted organic matter such as manure or garden compost.
It is done some months before planting to allow the turned over soil to weather and to allow the additions to be absorbed.
Many plants and most soils will give satisfactory results if “single dug”. This means digging a trench to the depth of one spades length. The soil from the trench is removed to the other end of the site and anothertrench is dug next to the first one, the soil from it being used to fill the first.
Organic matter should be mixed with this soil as it is returned either putting it in the bottom of the trench and then mixing it, spreading it on top of the soil before digging or forking it in from a barrow as the work proceeds.