When I signed up for Garden Organic‘s Heritage Seed Library earlier this year, I ticked a couple of boxes on the form to indicate my general willingness to take part in their 2016 trials programme. As well as participating in a seed-saving survey, I also said I’d like to help trial a potential new green manure seed: Persian clover (Trifolium resupinatum, meaning ‘having the appearance of being upside-down’).
As I’m sure most gardeners and plot holders are well aware, green manure is any one of a range of fast-growing crops that’s intended to cover a patch of otherwise un-used ground. The plants help to keep weeds down and then can be dug in to provide compost matter and food for worms, both of which help to improve soil quality.
At the weekend, the postman delivered a package from Garden Organic with two packets of clover seed: Persian and the more common red (Trifolium pratense, meaning ‘of the meadow’) variety. We grew the latter as a green manure last year, but didn’t get around to digging it in, and this was the general result:

(We got a lot of comments from our plot-neighbours about how lovely the patch looked and the bees went mad for the nectar, so we left it to do its thing. It went to seed and re-grew a second time, which I also didn’t get round to digging in, until I ended up clearing the patch earlier this week.)
According to the notes from Garden Organic, Persian clover – which is widely grown as a fodder-crop – is meant to be a little more no-dig-friendly, as the stems are quicker to rot down and can be left on the surface for the worms to deal with; unlike the red clover steams which tend to dry to a straw-like consistency and don’t incorporate into the soil unless you do dig them in.
The seeds need to be sown in mid-March, so I’d better get my skates on and decide where I’m going to put the two one-metre trial sections on the plot. I’ll be sure to take plenty of photos and record my progress as I go, with further updates here as the two clover crops develop.
If you’re interested in using green manure on your own plot or garden, take a look at the range of seeds available from sowseeds.co.uk sub-site www.greenmanure.co.uk, which is who we bought our red clover seed from, and read their notes on choosing the right green manure to see what’s best to sow where, when and why.