Green manures

Grazing rye green manure 

I have tried many different green manures. Several of the allotmenteers around my allotment first decided to go for grazing rye. It was expensive but it did the job very well. If I have the choice I will use grazing rye more than anything else. It produces a lot of leaves and a great mass of fibrous roots. The one drawback, if you can call it that, is that it does not fix nitrogen from the air (or I should say doesn't have Rhizobium bacteria). 

The legumes have these bacteria and fix nitrogen from the air producing nutrients, if the whole plant is dug in. 30% of the fixed nitrogen is in the root and 60% is in the stem and leaves. Where the other 10% goes I don't know. So in the legumes, I have used tares, lupins and am now using field beans.

I use ordinary lawn grass seed as a green manure and, although this is not quite as good as grazing rye, it is a fairly good second choice.

Caliente Mustard Green Manure

I have also used ordinary mustard and Caliente mustard. Caliente mustard is supposed to have pesticidal properties if you cut it up when digging it in. Mustard is great for covering a large area with weed suppressing green manure. It can be grown in the summer after things like potatoes and onions have been cropped. I have not tried any other of the normal green manures but sometimes, if I have any seed left over, I will just sow this to be dug in in the spring.

 The season for planting green manures is well past, although I was thinking of putting broad beans in the brassicae bed and hoping that they would produce something before I put the cabbage out in May/June time but I doubt very much if that would be successful.

Green manures will go in on any ground where crops have been harvested.