Green manure/cover crops

Why plant

For larger garden areas that won’t be dedicated to a winter harvest, planting green manure can help ready the ground for spring planting. The idea behind this is to have plant material that is nitrogen-fixing, and then using the harvested plant material for compost to enrich the soil for spring planting.

They also protect soil from erosion and compaction  during winter rains, and keep weeds down.

What to plant

Fast growing nitrogen fixers –

*Fava beans

*Faba (bell beans)

*Clovers

Alfalfa

Good cover crops but not nitrogen fixing –

*Buckwheat

*Annual rye

Oats

*Available by the pound from the Nursery

How to plant

Remove old plant material  (large roots, stems, fruit) from area. Rake smooth and sow seeds at a high density rate. Rake into soil. Add a layer on top if necessary to cover larger seeds.  Water in well.  Keep moist until germination (irrigate if it is not raining yet).

The easiest way is to compost in place. When the plants are in 80% flower, turn them under with a shovel preferably.  (Note if they go to seed, you will have to start the process all over again! ) Rototillers work, but do a lot of damage to underlying soil structure when used repeatedly. It takes about a month for them to decompose  this way( if the area is kept watered, either from rain or weekly watering if there is no rain)Dry plant material takes much longer to decompose.  You can also pull them up and toss them into a compost bin, and add compost back to the area when you plant.

To plant spring vegetables, put your new layer of organic matter/planting mix right on top and plant as usual . Less fertilizer should be needed to sustain your summer crop.