Discover Amazing Benefits of Green Manuring
The first and obvious green crop for digging in is weeds. When digging in these or other forms of green manure you need a wider trench than normal so that the green stuff can be skimmed off with about 2 inches of, turned into the bottom, given a few quick chops with a spade and clean soil turned over on top. The whole area is then left absolutely clean with no weeds or bits and pieces sticking out of the soil to go to seed and create more weeding in the future. The criterion of a successful digger is this clean finish.
An ideal time to sow for green manuring is directly after harvesting a previous crop, the soil is still moist and warm and all that is necessary is to scatter on the seed and rake it in. The clovers and vetches will, in addition to providing humus, supply nitrogen to the soil.
To obtain the best value from green manuring, the crop should be dug in when in full leaf and before the stems become woody and the leaf area deteriorates. For this reason I like the clovers which continue green well into the winter months and can be dug in at leisure. Another good subject for green manuring is the annual lupin which, being a legume too, also produces nitrogenous nodules on its roots. Perhaps one of the reasons why this ancient method of providing humus is not as widely used as it should be, is the difficulty in obtaining small quantities of the seeds.
Many allotment societies and gardening clubs buy in bulk to distribute to their members. Mustard and rape, however, are readily available and the value of the green stuff is out of all proportion to the small amount you have to pay for the seeds.
Chickweed may not be your favourite weed, but very often, particularly if the autumn is damp, masses of this may accumulate in rows of peas and so here the method is obvious. Don’t try to chop it up and rake it off as this only spreads the seeds. Instead dig out a trench, skim off both the pea haulms and the chickweed, and bury them at the bottom.
There is nothing in the rule book which says that all the crops have to be cleared before you can dig and the safest place for weeds is a good 10 inches below the surface. On sandy soils which do not benefit from early digging in the same way that heavy soils do, it would be better to use a clover mixture which will keep green over winter and can then be dug in during the early months of the year. Exposing light soils to heavy winter rains tends to leach out soluble nutrients such as nitrogen.
If you have a large garden with some dirty corners, plant comfrey. This is a perennial which can be mown regularly and is used either to dig in green or to provide a constant source of materials for your compost heap. As comfrey grows vigorously it will eventually smother out weeds. The flower is quite attractive in its own right. It will also stand a certain amount of shade and can be a good barrier crop against invasive weeds. Altogether it is a most useful plant even apart from its medicinal qualities.
There is no need to scatter fertiliser or even lime on your green manuring. Save this for dusting on the soil surface and raking in a fortnight before you sow or plant the following season.