Mulching is the action of adding a layer of material on top of the soil in growing areas of your farm or garden. This is one of the primary practices in permaculture, and in 'no dig' gardening or 'no till' farming. In a permaculture, 'no dig' garden, the gardener aims to disturb the soil as little as possible.  The soil is an ecosystem like any other, with many important elements that work together to allow for the flow of water and nutrients, and the growth of plants. In a 'no dig' permaculture system, the soil web is allowed to function as it should, without being disrupted by the agency of the gardener. 

Mulching is a method which allows for the integration of new organic matter and the addition of nutrients without disturbing the soil. What is more, by laying natural materials on the soil surface of our growing areas, we can protect the fragile soil ecosystem that lies beneath. Mulching is used to replenish and sustain existing growing areas, or can be used to build up new growing areas for your farm or garden.

One of the great things about the techniques used in mulching is that they can be used to create new garden beds. No matter what you wish to plant, you can create a fertile, moisture retentive place to grow in by sheet mulching an area with layers of natural mulch materials. Sometimes, these sheet mulch beds are called 'lasagna gardens' since the layers are built up in much the same way as you might make a lasagna in your kitchen.

Why Mulching is Important in an Organic Garden

An understanding of where and how we use mulches begins with an understanding of why we mulch in the first place. There are a number of reasons why mulching is important in organic gardens. These include:

• Mulching protects the soil surface from erosion and disruption.
• Mulching can add nutrients to the soil.
• Mulching helps soil to retain moisture.
• Mulching can help to suppress weed growth.
• Mulching can be beneficial to a range of wildlife, providing them with various habitats where various creatures can thrive.

What Materials To Use For Mulching

A number of different natural materials can be used to mulch your growing areas. These include:

• Wood chip or bark (Or sawdust/ wood shavings from sawmills etc. if untreated)
• Straw or 'Strulch' (Composted straw)
• Fresh leaves (from a variety of different plants)
• Leaf mould (Rotted-down autumn leaves)
• Grass clippings
• Compost (Home-made, organic compost is ideal)
• Well-rotted manure (Most manures will 'burn' plants when fresh and so should be composted thoroughly before they are placed around tender plants.)
• Dried bracken (or other dried plant material)
• Seaweed (Which is particularly rich in a number of micro-nutrients.)

The benefits of using natural mulch materials are that these materials can often be found for free in your garden or in the surrounding area. In addition, organic gardeners or farmers may also consider mulching certain plants with gravel, shingle, slate or other 'inert' natural materials, which, while they will not add much nutrition to the soil, can help to suppress weeds, or to improve drainage and prevent plants from rotting in waterlogged areas.

Choosing the Right Mulches

When it comes to applying mulch, it is always important to consider where the growing area you are mulching is located, and the plants that are being or will be grown there. The mulch that it is best to use will depend on these factors, as well as the local availability of natural materials.

Each of the mulches mentioned above has strengths and weaknesses in a given situation. While each may be excellent for some applications, the same one can also have a detrimental effect when placed in the wrong location. 

For example, wood chip or bark can be an excellent choice for mulching beneath trees or large shrubs, but may be detrimental when used around younger plants or annual vegetables. As the wood decomposes, this actually takes a lot of nitrogen from the soil, so may be harmful to small, leafy plants that need a lot of nitrogen to grow. Grass clippings on the other hand, are very high in nitrogen, so a mulch from your mown lawn could be ideal for members of the cabbage family, or other nitrogen hungry plants. This mulch may be too rich in nitrogen for other crops, however, so should be used with caution.

Whenever you are mulching an area, it is important to consider which plants are growing there, what nutrients they need, and what the conditions are like there. The state and appearance of the plants you grow will give you clues about what nutrients might be missing or in short supply, and what should be added to the soil. You should also consider which mulch will best be able to meet these needs. Considering these issues should help you to choose the right mulch for the job.

Whichever natural mulches you use, you will find that mulching is a vital practice on any organic farm or in any organic garden. Sustainability is important in any growing system. It is vital that we ensure our growing areas can be productive year after year, not just for a short period of time. Caring for the soil ecosystem and the things we grow through mulching is one of the most important ways to ensure the good health of our topsoil and plants. Sourcing and choosing mulches, therefore, is something every food producer should be sure to consider.