The No-Dig Method
No Dig method of cultivation can be used for two purposes: to provide a rich soil to grow in, and to clear a weed-infested growing area. Both instances require a great deal of surface mulch (well-rotted manure or compost). In principle, by avoiding digging you will not be disrupting the soil life, nor will you be exposing the soil to weed seeds. Instead the existing weeds are in darkness, which causes them to weaken and die.
For soil that is already cultivated, here's how :
- Step 1: 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 a rich and well textured soil.
- Step 2: You can plant or sow direct into the surface compost of newly-created beds, just as you would normally. You will find there are less weeds to hoe, they are easy to deal with in the soft surface, and 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.
- Step 3: Use a trowel to remove any weed regrowth through mulches because it can take up to a year for all the weed roots to be exhausted. Annual weeds die within 2 to 3 months; but perennials take longer – often up to a year. Only bindweed and marestail can survive, but are weaker.
- Step 4: 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
To clear a growing area of weeds, here's how:
The aim here is to exclude the light so weeds can't grow. So you need a combination of a sheet covering and a thick, deep layer of mulch. For the sheet covering, you can use layers of cardboard (which will degrade into the soil), or a thick membrane such as Mypex. Many prefer not to use plastic, and we advise to be wary of carpet as some dyes and mothproofing chemicals can be toxic. The deep layer of mulch can be half rotted compost, manure, leaves, grass mowings – or even a mix of them all, so long as it is more than 15 cms thick. There are two schools of thought whether the mulch goes under or over the sheeting. If under, then it will rot down and create a wonderful, friable soil texture which is not only rich but allows weed roots, such as bindweed, to be pulled out easily. If it is over the sheet, it has the benefit of keeping the sheeting in place. Both methods will make sure that absolutely no light can penetrate down into the soil. 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. When it's ready and weed free, remove the sheet and the soil will be ready for planting.
For further information on the No Dig process visit http://www.charlesdowding.co.uk/