In principle, by adopting No Dig gardening you will not be disrupting the soil life. This is the important micro-organisms, fungi and worms, that help feed plant roots.
You will need a large quantity of organic matter. You can use home-made compost, leafmould, well-rotted manure, green waste compost or even bagged peat-free compost.
To clear a growing area of weeds, a new allotment, or create a new bed:
You will need:
- Plenty of organic matter
- A sheet of light-excluding material, such as cardboard
The aim is simple - to exclude the light so weeds can't grow. And to cover the soil with a rich organic mulch.
- First, slash down tall weed foliage to ground level. Put it on the compost heap.
- Lay sheets of light-excluding material (cardboard etc) so the ground is completely covered. We don't recommend plastic unless it can be reused and won't degrade into the soil; nor is carpet a good idea. Modern carpets are treated with chemicals and dyes that can leach poisons onto the soil.
- Now put a deep layer of organic mulch. Use homemade compost, fully-rotted manure, leaves, straw, grass mowings – or even a mix of them all, so long as it is more than 15 - 20 cms thick.
- Tread it down firmly. Eventually, it will rot down and create a wonderful, friable soil texture that is not only rich but allows weed roots, such as bindweed, to be pulled out easily.
- If you use a horticultural membrane such as mypex, you can put the mulch under, not over, it.
- Either way, make sure that no light can penetrate down into the soil.
- In both instances, wait for 6 months at least for the weeds to die down and the soil organisms to do their work. Be patient! It can take up to a year to completely weaken the weeds, especially those with deep and extensive roots like bindweed, dock, and bramble. The soil has become so rich and friable that you will be able to pull roots out easily.
For an area that is already cultivated:
- Apply at least 15 cms or more of an organic, well decomposed mulch to your beds. You don’t need to dig beforehand, as soil organisms such as worms will rise to the mulch, eat and digest it, creating rich and well-textured soil.
- Firm it down.
- You can plant or sow directly into the surface compost, just as you would normally. You will find there are less weeds to hoe, they are easy to deal with on the soft surface. The soil beneath is firm but not compacted, as the undisturbed soil organisms develop a honeycomb of small air passages – perfect for plant root penetration.
- To sow seeds, use a rake to prepare a soft, crumbly tilth on the surface.
- Use a trowel to remove any weed regrowth through mulches. Annual weeds will die within 2 to 3 months, but perennials take longer – often up to a year. Only bindweed and marestail can survive, but they become noticeably weaker. And as the soil becomes more friable and richer, it is easier to pull out the long root systems in bindweed, for instance.
- Ongoing maintenance involves annual applications of just 5 cms or so of compost or manure. This should be applied ideally in the autumn, when crops are cleared, or in spring on beds where winter crops have been growing.