[RichardY]

Hello,

Can anyone advise me on intercropping green manures. I've ordered some Red Clover (500g), Lupins(1kg), Alfalfa(500g), Phacelia(250g) and a few Common Comfrey seeds (36). Is it worth getting white clover (as a lower groundcover), vetch, rye or ryegrass?

My plan is to rake a 1 inch layer of clay soil mixed with potash from several bonfires in the past, over some hard-baked  cracked bare clay soil. Then add the seed and cover with either some compost or some potash in effect sandwiching the seed. I'm planning on smothering out most of the weeds by intercropping green manures. Then leaving the plots to self seed. I've dug some drainage channels, to help prevent flooding. Thank you for any advice.

[Christine]

The red clover may well not come through as it prefers sandy soil as best and certainly never came through on the clay on an allotment I'm renovating. You would have done better with something like fenugreek.

[al78]

I have intercropped white clover and trefoil with brassicas a couple of years ago, and that seemed to work ok, in that the green manure provided a cover for the soil, I think it supressed annual weed growth, although the occasional perennial weed grew through it. At the end of the season it was fairly easy to dig the clover and trefoil into the ground. I have also grown phacelia in clumps around my plot which the pollinating insects like when it is in flower, it is good to grow it near things that you want pollinated for that reason.

I think vetch and rye are used more as a winter cover crop to help protect the soil from the worst of the winter weather (e.g. hammering and leaching of nutrients by heavy winter rains). These are chopped down and dug in early spring and left for about three weeks to decompose as they give off chemicals which inhibit germination of small seeds whilst they rot down, so you need to wait a bit after digging them in before sowing things like carrots. If you have heavy clay soil field beans are well suited for an overwintering cover crop.