I’ve just pulled out the spent peas and garlic and there’s time for cover crop before the next vegetables go in. I’ve got beans already planted alongside where the peas were, so before they cover the whole bed, I’m sowing cover crop on the unplanted side. On the empty garlic bed, cover crop will grow nicely until the winter brassicas (savoy cabbage, Brussels sprouts and kale, for example) are ready to transplant out. Right now they’re growing in pots on a table outside and when I’ve re-potted them and they’re about four inches tall, I’ll dig in the cover crop, add fertilizer and a bit of compost and transplant the seedlings. The bed might not be big enough so I’ll see what other space I can scrounge.
Cover crop is plants grown on bare soil for several reasons: they help clean the soil of possible disease organisms; they add their own nutrients and biomass to the soil; they help prevent soil erosion; and they retain nutrients in the soil. Leguminous cover crops like vetch, crimson clover, fava beans and peas also add nitrogen to the soil if you don’t remove the peas or beans from the pods or if you dig them under before they go to seed.
After 12 years of gardening my back yard, the soil has become so rich that the plants practically grow themselves. The combination of robust compost, organic fertilizer, trace minerals, compost tea and cover crops is making this soil more fertile than any soil I’ve worked before.
The best cover crops I’ve seen are combinations of a grain and legume because grains grow extensive root systems, adding large amounts of biomass to the soil, and legumes add nitrogen. The accompanying picture is a cover crop of corn and buckwheat. I also sowed crimson clover which didn’t sprout, dad blast it. I guess it was old seed that I hadn’t dated.
Most gardening authors don’t recommend corn as a cover crop, but it’s a grain, doesn’t harbour diseases that would affect the next crop and sends down deep roots, so if I turn it under while it’s still succulent, it should rot into a nice seed bed. And besides, I have a ton of corn seeds from last year’s crop. The buckwheat is a grass much like a grain that grows well in the summer and breaks down easily when I dig it under early September. Then I’ll sow the bed with a winter cover crop like winter rye and fava beans that I’ll dig in next spring. I’m leaving the hoops in place to drape Remay over until the seed has sprouted to keep out those rotten Stellar jays with nothing better to do than peck up every last seed.
One doesn’t need specific plants to use as a cover crop though. A farmer I know lets his acreage go to weeds and tills that in, presumably before it goes to seed itself. Though weeds certainly are better than leaving the soil bare, because they go to seed so quickly, it’s vital to dig them under before that. Neighbours don’t like your dandelion seeds blowing into their yards.