A permaculture guild is a companion planting scheme that emulates the production systems of natural ecosystems and incorporates different species of animals, plants and microorganisms which are assembled around a central plant for maximum productivity. The guild mimics forest systems with their multiple layers of vegetation, insects and animals which work together to ensure that the overall system thrives.
One single species cannot survive on its own but when combined, all these elements will experience increased growth. The plants and animals in a guild are carefully selected to boost the productivity of the central plant, cut down on the number of inputs and reduce the amount of work needed manage it. As a result, the whole system becomes more self sufficient and can sustain itself for a long period of time.
Plants and natural ecosystems need several components in order to survive. These include; nitrogen, moisture, pollination, mulch, pest control and many others. Each species in a guild helps to supply at least one of these components and keep the whole system functioning optimally. Guilds take advantage of properties such as nitrogen fixation and dynamic accumulation below the ground, pollination activities by flowers and fruit above the ground and shelter provision and shade provided by the physical structure of a central plant and many other benefits.
Choosing the plants that will work best in a particular guild is determined by several factors; including the function that a particular plant will serve in the guild, characteristics of the plant, landscape you are working in as well as the particular climate that you live in.
Each guild consists of several layers of plants above the ground matched by a similar network of roots below combined in a way that makes it difficult for predators and other intruders from penetrating into the system. Plants are placed close together and encouraged to form mutually dependent groups that utilize all the space around the central plant, keeping out weeds, providing groundcover that prevents erosion and retaining moisture in the soil which means less watering and digging.
A strong guild needs time to develop character and maturity. In the initial stages, the most important functions will include nitrogen fixing, nutrient accumulation, groundcover formation and pest control. The guild should therefore be created with these considerations in mind. Later, as the system matures, some of the plants can be thinned out to prevent competition for resources with the central plant.