In nature, soil is rarely exposed. So why leave it that way in the garden? Pamper your soil in the fall by covering it with plants…while there’s still time! Green manure cultivated towards the end of the season will serve as “cover” for your plantings during the colder months, before being buried in the soil once spring comes. The result: your soil will be protected from erosion, from compacting and from drying out. It will then be more conducive to the establishment or the survival of living organisms, in addition to being more fertile. So why not take advantage?
In September it’s “last call” for green-manure sowing. Sow the fertilizers suggested below after your summertime growing and before it freezes.
Grains like barley (Hordeum vulgare) and oat (Avena sativa) germinate even in cool temperatures. They’re not resistant to winter themselves, but will protect your soil from the cold and wind. Late in the season, opt for fall rye (Secale cereale), because in terms of hardiness it’s second to none. The biennial that it is, rye survives winter, and early in the spring the humidity of the soil is enough to bring it up. But careful! See that you mow it quickly after the spring thaw, because it becomes difficult to cut when mature, and resows if allowed to go to seed...Rye’s the ideal candidate for areas of your garden where you’d like to provide some competition for weeds in order to get the season off to a good start.
For guaranteed springtime vigor, growing broad beans (Vicia faba) is a terrific option. As with all legumes, it acts as a nitrogen fixer in the soil. When returned to the soil in spring, the small nodules release hydrogen as they decompose, making it available for the plants that you’ll be growing next.
Between two green manures, where does your heart lie? A number of producers offer a legume-grain mix. Pick up local, organic seeds from Québec-based seed companies. Most of them sell their green manure online and will deliver it to your door. You may also come across some in certain public markets or in agricultural cooperatives.
Cut and bury
In April or as soon as the ground thaws, it’s time to return the manure to the soil. In dry weather, cut it with pruning shears, with a lawn mower or an edger. Then, let the pieces dry completely before returning them to the soil, on the surface. Next, wait two to three weeks to take advantage of the decomposition of the manure in the soil. Then add a layer of compost, and plant in early May according to your region climate.
Growing green manure in the autumn extends the pleasure of gardening into the fall and gives us a head start on preparing the garden in the spring: a practice that unfailingly adds to a gardener’s happiness, not to mention the resilience of the garden!
Taking it further
Protect the soil, even when you grow in pots
In the fall, leave your unharvested plants where they are. Add a layer of shredded dead leaves or pieces of straw or else buckwheat hulls to the surface of your containers. In the spring, take out the biggest of the plants, lightly loosen the potting soil and replace a third of it with compost before planting again. As for clay pots, better to either empty them before winter or find some shelter for them in order to prevent cracking when it freezes outside.