Toby Buckland: green manures are the best way to help soil, says Toby
Toby doffs his cap to some of the most important plants he will be sowing in late summer: his precious green manures
EVERY manure has its own properties and purpose. Pig poop stinks to high heaven, but is the best thing to encourage tired hybrid teas to, well, come up roses, while pong-free alpaca pellets are so mild you can bung the dung straight on the garden without composting first.
But of all the cow pies, meadow muffins and farmyard fertilisers, there is only one manure that I’m happy to wade up to my armpits in, and that’s green manure.
Green manures, as I’m sure you know, are crops grown for the benefit of the soil. Rather than being harvested and eaten by us, they are dug in or left to rot down and release their nutrients where they are.
They’ve been around for thousands of years, and from the monsoon-soaked soils of India to the sun-baked fields of Ancient Greece, farmers in the know have sown them to fill the gaps as edible crops are harvested – protecting the soil and locking in nutrients until the growing season starts again.
As potatoes, dwarf French beans and herbs are harvested, I have a collection of green manures (see the panel below) to fill the spaces and, like animal dung, each has its own properties and purpose.
For suppressing weeds through winter, Hungarian grazing rye grass is my go-to, and its shaggy sward stores masses of nutrients for the crops that follow. Sown now, the roots have time to grow outwards, breaking up heavy soils.
In spring, the tops are turned into the soil but, as well as releasing goodness, for six weeks the rotting leaves will also emit a chemical that inhibits germination. This reduces weeds but also affects vegetable seeds, so plan to plant potted veg (beans) and potatoes as a follow-on, as they are less affected.
Hungarian grazing rye is also a pig to dig, so never grow it where acrobatics are required to bury the leaves, such as tall raised beds. For them, I use the yellow poached egg plant and phacelia. Both are loved by the bees, and the purple blooms of phacelia smell of Cherry Bakewell tarts – as far from pig dung as you can get!
“Protect the soil until the growing season starts”