Prepare the ground you want to sow by weeding it and the raking it over to loosen up the soil.
In a bucket mix together all the seeds you are using with at least as much sand or soil. This helps to spread the seed further and get an even covering. Then, using your hand, broadcast the seed as evenly as you can over the area you wish to cover. Then gently rake the seeds in so that most of them are covered with soil but you retain the even spread of seed across the area.
Give the area a really good watering with gentle spray on a hose or sprinkler. The area will need to stay moist but not soggy until the majority of the seeds have germinated. In warm weather this may mean watering it once of twice a day. You can also cover the soil with shade cloth to prevent the soil drying out and the cockatoos and corellas eating the seeds!
This is the easy step. Just the green manure grow.
When about 10% of plants have started flowering, it is time to dig the green manure in. Its important not to wait too long because you don’t want the green manure crops to set seed or you will forever be weeding their offspring out of your garden! When they have just started flowering, the plants are at the height of their nutrient density.
There are many ways to ‘dig in’ a green manure. My favourite, most lazy way, involves minimal soil disturbance and therefore minimal back breaking digging. Using my sharp spade I literally chop the plants off at the base and then chop them up with the spade. Inevitably some weeds or plants that you hadn’t intended to grow will have grown in amongst the green manure crop. They are all good biomass so I chop everything up. Some people use a mower for this step which chops the plants up much more finely. It means they break down faster.
When I’ve chopped up the plant matter I cover it with a thick layer of mulch. Using biscuits of lucerne, oats or whatever I can get my hands on, I create a thick blanket with the mulch which stops the fresh green plants from oxidising and losing all their carbon to the atmosphere (rather than it going down into the soil where I want it), keeps the moisture that is in the plants from evaporating and protects the worms and soil microbes whilst they do the hard work of breaking down all the plant matter and turning it into lush soil.
After 4-8 weeks (depending on your climate, soil and the season) you can make holes in the mulch to plant your heavy feeding crop straight into. The vast majority of the plant matter from the green manure should be unrecognisable and rich black soil should be what you find in its stead.
Now your soil is ready to house the seedlings which will become your autumn’s bounty. Healthy soil means healthy plants which leads to healthy people who eat them.