Permaculture methods for regenerating the soil

Don’t despair if your garden’s soil isn’t great – it can be improved!

Not all soils are equal. Some soil types are easy to work while others are a nightmare. The good news is that poor soil can, with understanding and patience, be regenerated to the point where it yields wonderful results. Healthy soil is key to healthy plants and a nutrient-rich harvest – it stands to reason that fruit and vegetables that are produced in poor soil will not contain the same nutrients and flavour as those grown in a healthy medium. Plants are also less affected by pests and diseases if the soil is in excellent condition.

What is regenerative permaculture?

‘Regenerative agriculture’ describes farming and grazing practices set to reverse the effects of climate change by restoring degraded soil and, most importantly, the level of organic matter on the land. ‘Permaculture’ is the practice of identifying all elements of sustainable living that are in harmony with nature and do not result in damage to the environment. The combination of these two concepts has laid a blueprint for farmers and gardeners to consciously dispense with age-old practices that damage the soil. In the agricultural sector, these include constant tilling of the earth, allowing land to lie fallow without growing a cover crop for protection, and repetitive planting of monocultures that deplete the soil of valuable nutrients that then require chemical fertilisers to restore some semblance of health to the soil. In gardens, the practices of raking up organic matter for aesthetic purposes and regularly turning the soil to aerate it are no more. Gardeners are now urged to build layers of rich, healthy organic matter, using plant material from their garden where possible, to improve soil health and provide optimal growing conditions for both ornamental and edible plants. While this might require a slight shift in mindset for some, the end result is extremely rewarding. Soil health improves dramatically, you won’t need to water the garden as frequently and you will notice an increase in the variety of insects and birds that visit your property.

Regenerating the soil

There are many ways to restore and maintain the health of your soil with minimal expense. No-dig practice: Regular turning of the soil damages its structure and exposes the beneficial organisms residing in that top layer to the elements. It also increases moisture evaporation, and that is why it is now actively discouraged. When planting into an existing garden bed, it is likely that there is already some organic matter in the soil. In that case, first remove any unwanted plant matter, lay down a thick layer of good-quality compost and plant directly into that medium. As you plant, the compost will automatically be incorporated into the soil, and the remaining compost will act as a layer of mulch. If, however, you are planting into virgin soil that is either compacted or has a high clay content, you can choose one of two methods. The first is to work over the top 10 – 20cm with a garden fork and then lay down a thick layer of compost before planting. Note that this action of turning the soil need never be repeated. By replenishing the layer of mulch several times throughout the year, you will notice a huge improvement in the structure of the soil over time. It can take as long as 3 – 5 years for the quality of poor or compacted soil to improve. The second option is to use the ‘lasagne bed’ method, where you create layers of organic material that soon combine and decompose to the point where you have a rich, friable base in which to plant. It is an efficient means of utilising garden waste that might otherwise end up on a landfill site, and is an excellent method for raised beds. At its base, layer cardboard boxes or sheets of newspaper to prevent weeds from popping up. The cardboard also absorbs moisture and releases it back into the soil slowly before eventually breaking down. On top of this add layers of absorptive material such as straw, hay and dried grass clippings. After that comes the layer of organic material such as compost, kraal manure, fresh garden waste or vegetable peels, and even some topsoil. This layer will increase the productivity of the bed. Repeat these layers until the desired height is achieved, and add a final layer of straw before watering the bed well. As the material starts to decompose, it will subside so ensure that you add sufficient material, especially in raised beds.

Mulching: Mulching is key to a healthy soil. The action of ‘mulching’ is a term used to describe laying down any suitable organic material on top of the soil that will insulate it against heat and wind damage, erosion and prevent moisture evaporation. Depending on the material you choose, mulch needs to be replenished several times a year as it is quickly absorbed into the soil, which is exactly what is needed. In the documentary Back to Eden, Paul Gautschi expounds the benefits of sustainable organic growing methods that can be implemented in diverse climates around the world. He cites his success of using wood chips as a mulch on hard, clay soil to the point where his soil is now friable and yields nutrient- rich crops – and he never waters his garden. Wood chips are not always readily available in South Africa because the machinery required is expensive, but there are other options that one can use as a mulch, such as compost, lawn clippings used in a thin layer, dry leaves, hay, straw, teff, newspaper, bark chips, shredded plant material, macadamia shells and newspaper. Choose the right material for your garden, bearing in mind that the more solid materials such as bark chips are used more as a decorative element and are not readily absorbed into the soil. 

Cover crops: Cover crops are grown on land that is fallow (devoid of plant material) to protect the structure of the soil until the next planting is done, and to address any problems in the soil. The benefits include reducing compaction, erosion control, protection from harsh elements, nitrogen fixation and weed suppression, to name a few. While this sounds like something you would only practice in agriculture, the benefits are enormous in gardens too, where areas of soil might be lying bare because you haven’t yet decided what to plant. Cover crops may also attract pollinators and add temporary colour to your garden. About three weeks before you are ready to plant, turn the cover crop into the soil so that it partially decomposes. This is referred to as ‘green manure’.

Food forests: The concept of the food forest is a relatively new one in this country for most home gardeners, but one that works well when planned correctly. It is a permaculture term for creating a long- term, sustainable food garden all year, where different layers of plants benefit one another and, ultimately, the soil. It differs from the traditional way of planting crops in organised rows in that it emulates a forest structure. In essence, the typical forest habitat is studied and then applied on a smaller scale specifically for food production. There are seven layers to the food forest: tall fruiting trees to emulate a forest canopy; low trees to slot in beneath the first layer; fruiting shrubs such as gooseberries, blueberries and raspberries; tall herbs, including perennial herbs and those that self-seed; groundcover crops such as strawberries and creeping herbs; vines such as melons, cucumbers, grapes and kiwifruit, and other vegetables that require support, and, lastly, rooting plants like onions, garlic, potatoes and sweet potatoes. Once a food forest is established, it should take care of itself, with the upper canopy generating sufficient mulch by shedding its leaves to feed the soil and keep it moist. By choosing leguminous trees, nitrogen will be added to the soil via their root system. Root hairs trap specific types of bacteria, which then penetrate the root cells. Over time, the root develops a nodule containing a package of nitrogen that either feeds the tree or releases into the soil, making it available to surrounding plants and reducing the need to feed with fertilisers.