Climate change, bio-diversity, water management, carbon sequestration, soil fertility, weed suppression – what have all these in common?
Green Manures are like security blankets, to fill in spaces as edible crops are harvested or ground cleared. These are plants grown to improve the soil and help regenerate the structure and fertility thereby retaining moisture and nutrients, whilst stifling weeds.
It can sound very off-putting; sowing at the designated time, digging in before flowering and other horror tales but choosing the right one for your situation can contribute great benefits to your soil.
In my new garden, I have a heavy compacted clay soil, once buried under a concrete patio. Bringing it back to life is a time -consuming, long term process. I have learnt not to walk on the soil – my footprints soon become waterlogged puddles; turning the ground was hard work and achieved little once I had initially broken through the pan (hard compacted layer). I have recovered about a third of the space, mulching with composted bark, my own hot bin compost and growing green manures. Whilst not the crumbly loam I once gardened on, it is much healthier with worms and other beneficial insects evident.
Adopting a ‘no-dig’ practice was part of my success and can easily be incorporated into any space with a little planning.
Sow now; clovers and vetch by the beginning of September otherwise they don’t develop sufficient growth to cover the surface. If you have no space then, try grazing rye, field beans or forage peas. Annuals are the best for no-dig practice, dying off naturally as the season ends.
Phacelia is easiest, crimson clover too with its spectacular display ( red and white clover are perennial and often more persistent). Vetch is a good nitrogen -fixing choice, as are peas and beans if sown later in the autumn.
Once the plants have died down I cover it with a mulch. In the past I have used sheets of cardboard weighted down and covered with the layer of compost; not so pretty but the worms liked the cover. Or depending on the weather and growth of the plants I have chopped off the foliage and cut it up, before covering with the mulch. (The tougher stalks I have pulled out and added to my hot bin.)
A good information source on green manures, choosing and growing the right ones for your soil is
https://www.gardenorganic.org.uk/expert-advice/how-to-grow/green-manures-guides