Forest gardens are truly incredible things. Forests are like nature’s own version of a permaculture system, being self-sustaining, diverse and productive. By observing and copying nature in this regard, we can utilise the benefits that nature has shown us to create a forest system of our own that is respectful of the earth and provides an abundant harvest.
Forest gardens work by aping the layered composition of plant life in a natural forest. Tall trees – such as fruit trees – are the topmost layer, providing the canopy, then plants of different heights and characteristics are planted beneath, from dwarf trees and shrubs to companion plants, vegetable crops, herbs and groundcover. A forest garden can also contain climbing plants that grow up the trunks of the trees.
Given the right sort of climatic and topographical conditions, nature will instinctively move towards a forest environment. Different types of plants provide advantages that promote growth of other species in their vicinity, and this has a knock-on effect that includes binary relationships between plants, insects, soil and animals. In nature, plants want to grow and flourish, and they seek to populate environments in which the chances of doing so are maximized – a forest is one of the most fruitful places for this to happen. As a guiding principle of permaculture is to learn the lessons of nature and seek to use that knowledge, copying the structure of a forest in a garden makes perfect sense.
One of the primary problems with modern, industrial agricultural methods is the planting of monoculture systems. Growing single crops is detrimental to biodiversity, and creates more vulnerable ecosystems (see more on this below). Permaculture, therefore, promotes the idea of maximising biodiversity in food growing systems. A forest garden is one of the best ways to increase the biodiversity of an agricultural ecosystem. A forest garden offers so many different niches within it that plants can take advantage of, increasing the number and density of plant species within the ecosystem.
Variety of Habitat
This abundance of biodiversity has another effect; it provides a large range of different habitats. This in turn attracts a variety of local wildlife, making for a more dynamic environment. The variety of plants will bring many different species of insects to the forest garden (which then pollinate the plants within it, adding to the self-sustaining nature of the garden). This influx then attracts birds and insect-eating reptiles and mammals, which are then food for larger mammals. The variety of vegetation will also attract different types of herbivore, although you can plant your garden in certain ways to minimise the damage by deer, say. One must also remember that, not only does this heightened influx of animals aid the biodiversity of the forest garden, it also gives more opportunity to view wildlife, which is a great pleasure.
Linked to the notions of biodiversity and variety of habitat is the concept of resilience. As we know, agricultural systems that have a single crop are highly unstable and precarious. A period of poor weather, a transmissible disease or the invasion of a pest can decimate the crop and the farmer is left with nothing. In a system such as a forest garden, where there are many different species of plants, the whole ecosystem is much more resilient to devastating events. So, even if there is an unexpected event that hits a certain species of plant hard, there are many others in the system that, due to their different chemical or physical composition, can withstand it. This means that you are extremely unlikely to face a barren harvest from a food forest.
A mature forest garden gives a large yield of edible foodstuffs. The variety and biodiversity inherent in the design – and with judicious planting – means that crops are available throughout much of the year. Companion planting and the variety of niches and microclimates with a forest garden ecosystem contains result in ideal conditions for plants to thrive, and so produce their edible parts, be that fruit, leaves, vegetables or roots. In fact, forest gardens typically produce an abundance of food, meaning that you will have a surplus to preserve for the winter months or trade and distribute with your neighbors or through a market stall.
With so much plant life in a forest garden, the leaf litter that inevitably falls to the ground serves as a natural compost. The abundance of plant material means that microorganisms and bacteria are supplied with a lot of nutrients and so quickly turn the leaves into compost and incorporate it into the topsoil. The shade and groundcover provided in a forest garden also helps to prevent soil erosion and limit the evaporation of water from the soil.
Natural Pest Control
With the great biodiversity in a forest garden attracting many species of insects, pest control occurs naturally. By providing a permanent home for lots of types of insect, the forest garden finds a sustainable level between predatory insects and those that eat plants. And the predatory insects are prevented from becoming too numerous by the birds and smaller animals that are attracted to the forest garden to feed on them. Nature again finds the right balance.
In nature, forests exist and thrive perfectly well as their own closed system. They don’t need the addition of extra fertilizer, the removal of weeds, the spraying of pesticides and so on to keep them flourishing – they evolve and adapt to incorporate change. Forest gardens do the same thing, meaning that the human effort required to maintain them is minimal. Of course, permaculturists looking to initiate a forest garden will need to put some time into planting and working with the land (such as mulching, compositing and so on) to ensure the best start to the forest, but once the forest garden gets going, it requires very little maintenance. The systems of planting that go into a forest garden perpetuate a self-sustaining system, meaning that, from a mature forest garden, the permaculturists really only has to harvest!