Maybe it was a duff pack, but I will never buy green manure again. Can't recall what kind it was, but I sowed it about 8 weeks ago on an essentially weed-free patch following garlic harvest. Went back today with a view to digging in, but beneath the surface some kind of weed has taken hold. Can't identify it other than to say it's like "underground grass" with shortish roots....the kind you get when you first take on a plot, is everywhere and takes weeks to dig out completely. Taken 3 hours to clear just a small area. Too much of a coincidence to think it unrelated to the green manure. Very disheartening.
