With more and more people moving away from the use of animal products, green manures are becoming increasingly popular.
They are cheap and easy to grow and they also remove the chore of sourcing and moving animal manure around your plots!
I know a lot of people love to use animal manures but with many people trying to be as organic as possible on their allotments and kitchen gardens, it can be difficult to source organic animal manure. People often don’t think about how the animal was raised and how this could affect their overall organic mission. For anyone who sources animal manure this should be at the forefront of their minds.
Green manures are basically plants that are grown for their nutrient value and their ability to improve and feed the soil.
They are often used as a cover crop so that soil is not left bare. A bare soil will quickly loose moisture and valuable nutrients. Once they have grown, their foliage is usually chopped down and left to decompose which increases the organic matter in the soil. The higher the content of organic matter in our soils, the better they are able to withhold moisture and vital nutrients which will benefit both the soil life and the next crop. Not to mention, a soil that can retain moisture will help us gardeners on those hot days when watering can quickly become a chore.
Green Manures provide habitats and food for pollinators and other beneficial insects and also provide both food and habitat for our living soil organisms. If we can encourage more pollinators and beneficial insects into our allotments and kitchen gardens, it will help us to create and build our own self-sustaining eco systems and will help us fight pests in a natural way.
There are many different types of green manures available. There are some that are best used as part of your crop rotation and some that are not as fussy. To increase nutrient diversity, you should try and mix multiple varieties together.
We get asked a lot about how to use green manures in a no dig system as many people are under the impression that they need to be dug into the soil.
In a no dig system the goal is to disturb the soil as little as possible so as not to damage the soil life (or disturb the weed seeds!). Additionally, the less we disturb the soil, the more carbon is stored and not released into the atmosphere.
In a no dig system you should be aiming for green manures with soft stems and foliage such as phacelia and buckwheat. They will be a lot easier to cut down and it will be quicker and easier to incorporate these into the soil. Avoid rye in a no dig system as, like any grass, they can be extremely difficult to remove.
Green manures should be cut back before flowering as, when they flower, the stems will become much tougher and woodier and they will be much harder to incorporate.
In a no dig system the ideal green manure varieties are ones that you can ‘top and chop’ – the foliage will break down much quicker if you chop it up when you top the plants. You can also add a layer of compost on top of the mulch then this will also help to suppress regrowth.
For a longer-term solution, we can use things like white or red clovers. White clovers make a lovely ‘living’ mulch and are perfect for under planting under soft fruit bushes as they are low growing. They will also help keep the other weeds down!
Red clover is also a good long-term solution and you can grow a patch of this to be able to keep harvesting the foliage which can be chopped multiple times a season and used as a mulch.
Green Manures really are a fantastic way to keep your soil alive and healthy in a plant-based way and will also encourage pollinators and other beneficial insects to your garden.
If you are interested in using green manures in your kitchen garden or allotment we have put together a carefully selected variety of seeds which are perfect for use in your no-dig garden! Click here for more info