Skip to main content

Every now and then, I plant a green manure crop in my garden.

The term green manure is a name given to a variety of fast growing, leafy, temporary plants, usually grown from seed for a few weeks or months, then they’re chopped down prior to flowering and going to seed. The plants are dug into the soil or they can be left on the surface as mulch (I prefer to dig them in). Green manure is a brilliant way to add organic matter to your soil and increase soil fertility.

In addition to improving the soil, green manure crops can have loads of benefits such as reducing soil compaction, improving drainage, suppressing weeds, stabilising soil and minimising erosion.           

Some of my favourite green manure crops for Perth include Buckwheat, Fenugreek, Mung Beans and Mustard but there’s loads of warm season and cool season crops to choose from.  

Different green manure crops can offer various benefits.

Weed suppressants include Buckwheat and Lucerne. 

Nitrogen fixers such as Clover, Beans, Lucerne and Peas will provide lots of nitrogen to the following crop planted.

Biofumigants like Mustard release beneficial gases as they decompose in the soil and they can help to control root rot fungal pathogens and root knot nematodes.

Scatter your seeds in the area where you want to grow your green manure, lightly rake over them and water them in. It’s generally that simple. Give them regular watering. To get the maximum benefit from your green manure crop, chop the plant up as it starts to set flower as the nitrogen content starts to decrease after it has fully set flower. Once you’ve chopped your crop and dug it into the soil, allow at least a month before you plant your next plants. If you want to plant the bed sooner, maybe just use the green manure as a mulch.