One of the keys to successful organic growing is diversity. The more plants you can include in your planting scheme, the better. A polyculture is a type of planting scheme that you should definitely consider. In this article, we’ll discuss the idea of a polyculture, what it is, why they are a good idea, and how to go about creating one in your polytunnel. So keep reading to find out more.
What is a Polyculture?
A polyculture is a ‘guild’ or group of plants of different species that are planted in the same growing area. Traditionally, gardeners plant different crops in rows, or in different zones. But creating polycultures is a different approach.
In traditional farming and gardening, growers often create mono-cultures. In a mono-culture, only one type of plant is grown on one patch of soil or one garden bed. But in a polyculture, different plants are planted between and alongside one another.
There are several different types of polyculture that you can create. Some polycultures, for example, may include one main crop, with other companion plants planted in between the plants or on the fringes of the area. The technique of creating such a planting scheme is often called ‘intercropping’ or ‘companion planting’.
When polycultures centre around a key plant or plants, they are known as ‘guilds’. Companion plants in a ‘guild’ are primarily chosen for the benefits they can bring to the central species. Guilds are often created around fruit trees, for example. But they can also be created in an annual fruit and vegetable garden. For example, you might create a guild around your tomato plants, to help them fruit abundantly later in the year.
Other polycultures are simply collections of plants that enjoy and thrive in the same or similar growing conditions. In such a growing area, plants are chosen primarily because they all like the soil and climatic conditions that are found there. A good example might be a growing area with Mediterranean herbs, for instance.
Why Create a Polyculture in Your Polytunnel?
So, why is creating polycultures of plants such a good idea? There are a great many reasons why a polyculture planting scheme could be the best use of the space in your polytunnel.
To Boost Biodiversity: First of all, it is important, as mentioned above, to create as much diversity as possible in your garden. The more biodiversity you can create, the more beneficial relationships there will be between those plants. The more beneficial relationships between plants you can create, the more stable and resilient your garden will be.
What is more, when you grow a wider range of crops, you avoid putting all your eggs in one basket. It is much more likely that you will have at least some positive results, even when everything doesn’t quite go according to plan.
To Improve Resilience To Pests: Of course, boosting plant diversity will also attract wildlife, and boost the variety of animal life that is to be found in your garden. This too can make things easier for organic gardeners. Attracting wildlife to your garden is one key way to create balance and avoid problems with a wide range of common pests.
To Protect and Improve the Soil: Another reason that creating a polyculture is a great idea is that it will help you to protect and improve the soil in your growing areas. When you sow only one type of plant in a particular area, the soil ecosystem can become depleted and imbalances can creep in. By planting a carefully selected group of plants, you can make sure that the soil remains healthy, and even improves over time.
To Increase Your Yields: Polycultures are not only good for the ecosystem in your polytunnel garden. They can also help you make sure that you make the most of all the space (and time) that is available. The plants in a polyculture are usually quite densely planted, and you can grow more in a given area.
While the yield of a particular plant may be reduced when other different plants are sown nearby, additional yields often mean that overall yield is increased. Polycultures can also allow you to make the most of space by sowing quick-growing additional crops between others to harvest before the space and nutrients are required by slower growing companions.
To Create Beautiful Growing Areas: Polycultures are not only very productive, they can be very beautiful too. When you grow a wide range of fruits, vegetables, herbs and flowers, you can create a scheme that will produce plenty of food, but also delight the eye.
Choosing Plants For Your Polycultures
When choosing plants for your polycultures, it is important to understand why and how certain plants can help those around them. Choosing plants for a polyculture is not an exact science. In fact, scientists actually know surprisingly little about how different plants interact.
Often, finding out which plants work well together and which do not is a process of trial and error. Though we can learn a lot from various studies that have been undertaken. And there is also a large body of anecdote from other gardeners from which to draw.
Generally speaking, plants in a polyculture will benefit others around them by:
Providing some environmental benefit:
Casting shade, for example, or covering the ground to reduce water loss from the surrounding soil.
Dynamically accumulating nutrients:
Some, for example, are nitrogen fixers, which co-operate with bacteria in their root rhizomes to draw nitrogen from the air and make it available in the soil. Others have deep roots which can draw nutrients up from deep below the ground where other plants’ roots cannot reach.)
Repelling or distracting pest species:
Some plants will repel certain insects, for example, while others may act as trap crops to draw pests to themselves to keep other crops safe.
Attracting beneficial wildlife:
Other plants will draw in pollinators, or predatory insects or other wildlife to help keep pest species numbers down.
Improving the taste or yield of another crop:
Some plants are also said to improve the taste or yield of another crop when planted nearby. And while the evidence may be lacking for most combinations – there is no harm in giving the combinations of plants a try.
Considering the Needs of Your Plants
When choosing plants for a polyculture, it is important to think about the needs of each of the individual plants in question carefully. It is crucial to think about their requirements when it comes to light levels, temperatures, humidity, moisture, soil type and soil pH. You should also think carefully about what nutrients are required by the plants at different stages of their growth, and in what quantities.
When creating polycultures, you do not need to be an expert right away. But the more you can learn about the plants that you want to grow, the better able you will be to meet their needs. The more closely you can meet their needs, the higher yield you can achieve, and the better your results will be.
An important part of creating successful polycultures is anticipating potential problems. Think carefully about how you might solve them through companion planting.
For example, if pollination rates have been less than ideal, think about how you could draw in pollinators with other plants in future seasons. If you’ve had an aphid problem, think about planting to encourage ladybirds, lacewings and other predatory insects to move in. Has water evaporation made it difficult to keep up with watering needs in your polytunnel in the summer months? Think about plants that will shade or cover the soil, and keep watering needs down. These are just a few examples.
Considering Your Own Needs
When creating polycultures, it is important to think about the needs of your plants. But it is also crucial to think about your own needs. Effective polycultures should provide you with added value, compared to growing just one crop in each growing area. Think about how each plant can benefit you, as well as benefiting its neighbours. Some may provide more than just the help described above. They may also provide an additional edible yield in their own right. (For example, basil and oregano sown around tomatoes or peppers.)
Polycultures are what we naturally find in the wild environment. But in our polytunnels and gardens, we are shaping that type of growing environment to meet our own needs. So you can let nature reign. But it is always important to also keep your own needs and wishes in mind.
Do you grow your food in polycultures? Let us know in the comments below.
Elizabeth Waddington is a writer and green living consultant living in Scotland. Permaculture and sustainability are at the heart of everything she does, from designing gardens and farms around the world, to inspiring and facilitating positive change for small companies and individuals.
She also works on her own property, where she grows fruit and vegetables, keeps chickens and is working on the eco-renovation of an old stone barn.