COP26: Agro-forestry – a forest in your garden

Agro-forestry is not a term that would have many considering changing their gardening habits, and looking at definitions, for example from the Woodland Trust, could be off-putting. However the principles of agro-forestry can be applied to your garden (you don’t need a farm, a forest or even a garden) and will benefit you and the environment. ‘Forest gardening’, growing edible plants in a low maintenance environment, is a friendlier term.

A walk in the woods: agro-forestry in nature
A walk in the woods: agro-forestry in nature. Image by Image by Greg Larcombe from Pixabay.

There is nothing new in this approach. In many ways it recreates the way people lived thousands of years ago and still live today: sustainably, in balance with the environment, as hunter gatherers. With the development of agriculture and machinery, including some key developments from East Anglia such as crop rotation and self sharpening plough shares, we moved to monocultures and industrialisation. This move was reflected in allotments and productive gardens, with crops grown in rows.

The principles of forest gardening (let’s take a walk)

You may well already know the basic principles of forest gardening. Do you remember, from your school days or from helping children with homework, the layers of a rainforest? Each layer contributes to, and sustains, the others, achieving a greater diversity than would be possible with fewer plants. Imagine yourself walking into a woodland or a group of trees, maybe a park if you live in an urban area. You will see the layers: the ground below your feet with the soil and the roots, the surface of the soil with herbaceous ground cover, then a shrubby layer (maybe a hedge) followed by low trees under the canopy of the taller trees with climbers trailing up. You will have felt, as you walked under the trees, the light levels and quality of the light change, the cooler temperature (or warmer in the winter) and the moisture in the air.

Forest garden layers in agro-forestry
Forest garden layers in agro-forestry. Diagram by Graham Burnett. Image by Quercusrobur at the English-language Wikipedia, CC BY-SA 3.0, via Wikimedia Commons licensed under the GNU General Public License

There is an excellent, small scale, cultivation method that illustrates forest gardening system, albeit without the trees: the ‘three sisters growing’ system used for centuries by the Iroquois and other peoples of North America, combining maize, beans and a squash. Maize gives support for the beans to climb, the nodules on the beans fix the nitrogen the plants need, and the squash covers and shades the ground. This moderates the temperature, reduces competition from other plants, and stops water evaporating from the soil surface. In addition to providing most of a person’s nutritional needs, this method has double redundancy (as used in aircraft engineering): if one crop fails there are two others to sustain the community.

Soil: the key to agro-forestry

Soil is the foundation of any garden. We have become used to cultivating (digging) the soil for growing food, as many allotment growers still do, with the addition of artificial fertiliser; but both these methods damage the soil’s natural balance. The Second World War saw the no-dig methods put to one side and the manufacture of nitrogen fertilisers (the Haber Process) replacing natural organic material. Since then there have been positive changes and no-dig, organic gardening and permaculture are no longer considered unusual.

Forest gardening aims to create a natural balance in the soil, encouraging beneficial fauna and flora with minimal disturbance, and allowing the leaves of the trees and shrubs to build up on the surface, creating a circular economy in the garden. As crops are taken from the garden, it’s important to compost waste plant material and return it as mulch. Night soil was an normal part of cultivation before sewage systems became widespread. However, that might be a step too far for many gardeners, and care needs to be taken as toxic elements such as arsenic can build up in some crops. With the shade above, plants to cover the soil and the addition of organic matter (which retains moisture and nutrients), a forest garden needs less watering, and with careful rainwater collection the garden can reduce the need for mains water.

Agro-forestry promotes diversity

Above the ground diversity is equally important; forest gardens contain many niches where organisms such as fungi, insects, mammals and birds will flourish. Some of these will be beneficial, some will not, but the key is balance. This diversity will bring with it natural pest control, but it needs a change in thinking on the part of the gardener, and the acceptance of a certain level of loss. Companies involved in breeding and selling predators will sell gardeners the pest first so that the predators will have sufficient food to multiply, such as white fly before the parasitic wasp Encarsia formosa. The forest gardener, on the other hand, does not need to worry about buying in predators: creating the right environment and adopting sustainable methods will build the diversity naturally.

Can you do it?

Forest gardening has many benefits but could be off-putting. How many people have a garden big enough to plant a forest? There are many without even a garden. Other questions arise: can the garden be attractive and have flowering plants? Can it have a lawn? The principles of forest gardening can be applied to any situation and can have an attractive design.

The author demonstrating agro-forestry
The author demonstrating agro-forestry in a planter with a ‘red design’ theme. Photo by Jennie Pedley. Used with permission All Rights Reserved

Any change in your gardening habits that benefits the environment, however small, will make a difference. One tree can be viewed as a ‘forest’ and layers created underneath. If there is not enough room for a tree, how about a shrub? If you have no soil, a mini forest garden can be created in a planter or a porch. Even a windowsill can become productive using all, or some, of these principles. As for lawns, there can be an area for enjoying your garden created in the style of a glade, which slowly gives way to meadow flowers and on to the forest garden. In designing the garden all the normal elements can be included, such as colour, texture, flow through the garden with paths, water. There are many resources available with plant suggestions and support; here are 30 plants in a forest garden in Scotland. Forest gardening is the same as any other gardening, there are lots of ways to do it, and experimentation and evolution is the way to go. You could do it.