When we took over our plot four years ago the soil was in pretty poor condition. The plot hadn’t been worked for a few years and the soil was very compacted and looked generally lifeless. At the time the mushroom compost source had dried up and there was no advertised opportunity to source farmyard manure.
During the first two winters I sowed several types of green manure – clover, grasses and mustards. The grasses were less than successful: coverage was patchy and the results were easily confused with grassy weeds that grew naturally. The mustard was more successful, however, and provided a good, thick coverage of green and a rich network of fibrous roots. Both greens and roots dug into the soil easily in the spring time and I got the impression they were helping break up the compacted soil.
However, the following year I managed to source some dung and chose to dig that in in the autumn and over the winter instead of sowing a green manure crop.
I see the RHS recommend some green manures, but also point to problems they can create.
This year I am not sure what to do. I wonder what others feel about green manures and which if any they use and recommend? What are the pros and cons in your experience?
Update: Thanks go to Alison for this very useful link to the Green Manure Company.
Alison, Plot 80
I haven’t tried green manure myself, but a friend at the Greyhope plots speaks well of Phacelia, which we were discussing as something I could use in my wild edging areas that are for bees etc. He says this about it as green manure:
That green manure is phacelia:
http://en.wikipedia.org/wiki/Phacelia_tanacetifolia
You would need to get it in very soon for it to produce any bulk as green manure. Not always guaranteed to survive winter. To guarantee some for flowering next summer, suggest save a little of the seed for spring planting.
http://www.greenmanure.co.uk/seeds/phacelia-green-manure-seeds/ here it cautions against self-seeding but I haven’t found it a problem. Very easy to pull up the odd one that grows in the wrong place.
Norman
Thanks Alison, very helpful and very useful links. Norman
Alison
You’re welcome. I wonder if anyone knows about using field beans as green manure, too. Could be good for the nitrogen and leaf volume, but maybe not good ground cover.