Forest Gardening in Clean Slate
A new age for forest gardening?
Published in Clean Slate, Spring 2009.
Forest gardening offers an environmentally sound way of growing without the back-breaking work. But has it has it lived up to expectations? CAT Display Gardener Chloe Ward considers the possibilities for this innovative technique.
I remember clearly the moment of my conversion. 1991 saw the publication of Forest Gardening - the launch of a new way of growing food. It was the most environmentally sound system you could imagine. A vision of food production that was not just low impact but actively beneficial. The idea was enthralling to an aspiring ecological grower. It gave a new direction for the future. I was instantly seduced.
Robert A de J Hart (1913-2000) was inspired by the home gardens of the tropics such as those in Kerala, India, in which a wide variety of food plants grow in a small space, above, below and around each other in an organised tangle, similar to the natural forest that grows nearby.
It made perfect sense. Why grow crops in one thin layer spread over the earth's surface when nature makes use of vertical space right up to the tree canopy? Robert set about developing a system of three dimensional food gardening for the temperate environment. He designed a garden comprising a mixture of edible plants: trees and shrubs with bushes below and a ground layer of perennial or self-seeding plants below these.
A garden that looks after itself
Forest Gardening explains that the system is low maintenance because the plants look after each other. In Robert’s own words, the forest garden is, ‘self-perpetuating because almost all the plants are perennial or active self-seeders; self-fertilizing because deep rooting trees and bushes draw on minerals in the subsoil and make them available to their neighbours; self watering because the plants tap the spring-veins in the sub soil and pump water up for the whole system; self-mulching and self weed-suppressing because herbs like mints and balm soon cover all the ground between the trees and create a permanent living mulch; self-pollinating because the trees are selected to be mutually compatible or self-fertile and because the flowering herbs attract pollinating insects; and self-healing because the aromatic herbs deter pests.’
Robert saw the garden as an instrument for social change. He had a vision of many small, self-sufficient communities with forest gardens providing for their needs. A diverse diet would increase health, small scale food production would reduce competition for resources, and an ecological approach to growing would reduce problems of soil erosion, biodiversity loss and climate change. ‘The world desperately needs countless millions of trees to counter the greenhouse effect. There's no reason why the necessary trees should not be fruit trees.... If one could get 100,000 Londoners to plant ten trees in their back gardens that would be a million trees which would be something of a forest.’
Robert's own garden showed that it could work. Just an eighth of an acre, but containing over seventy species of edible plants, it provided him with fruit, salad and herbs for eight months of the year. He chose proven staples, such as apples and pears in the tree layer, blackcurrants and gooseberries in the bush layer and lemon balm and mints as ground covers. But he also experimented with less well known edibles such as juneberries, chequerberries, bamboo shoots and tree onions. He found the maintenance it required was satisfyingly low - a little weeding, but mostly harvesting.
Lessons from the garden: applying the techniques to agriculture
Most of our food is, of course, produced by agriculture, not grown in home gardens. But forest gardening contains a wealth of inspiration for the innovative farmer – in pest control, soil care and water conservation. A forest garden suffers very little from pests, which do not get the same hold as they do in monocultures. In agricultural systems, the same principles can be used by interplanting and growing a mix of varieties. A forest garden is rarely dug and its soil is protected by mulches and living covers. On a larger scale sustainable systems use minimal tillage and covers of green manures. A well cared for soil with high organic matter levels holds on to its moisture in times of drought.
‘This is not high horticulture,’ wrote Robert, ‘those who cannot stand the sight of a weed, or a gate tied up with string would do well to steer clear.’ Robert's writing was inspirational, making us believe anyone could do it, and we flocked to his garden for his patient guided tours. Throughout the country, forest gardening disciples set about putting his vision into practice.
CAT was no exception. In our old neglected orchard, I set about making a new Eden. I mulched with more cardboard than I'd ever seen, propagated every edible perennial I could get seed for, applied for grants, held volunteer days and spent many long days in the sun (but mostly rain) working towards my goal. The result - enough lemon balm to feed the world, some odd-tasting berries, salad that you really had to try hard to like, lots of plants that you can ‘cook like spinach’ and a bit of a couch grass problem. The garden was way too big to maintain and no one really wanted to eat the stuff that came out of it. I'd made every mistake in the book and added a few appendices of my own.
I cannot say my garden was a ‘failure’. It taught me a great deal. It produced a wide variety of edible stuff and what remains of it now is a good demonstration of which plants can survive total neglect. If it didn’t quite live up to expectations at least I know that I was not alone. While there are people who have made it work, notably Martin Crawford of the Agroforestry Research Trust, they tend to be those who are keen to experiment, both in the garden and in introducing unusual foods into their diets. But with so much enthusiasm in the UK, we should not be short of successful examples by now. So why does a thriving forest garden seem to be such a rare thing?
Firstly, there’s our climate. We are lacking light. In the tropics the understory plants benefit from a bit of shade. Here, they struggle to photosynthesise. In a temperate forest the ground is relatively bare, with vegetation springing up when a large tree dies, or early in the year before the trees come into leaf. It is where the sun does penetrate that we get multi layers of plants - a south facing woodland edge or an open glade. Temperate forest gardens need to mimic these ecosystems rather than a closed canopy woodland.
And then there are the gardeners. The newly converted forest gardener tends to be full of wonder and vision, and of a certain rejection of conventional gardening. They can be heard saying such things as, ‘I just want my garden to evolve organically,’ and, ‘these hawthorn berries have a wonderful flavour.’ In the rush towards ideals, was it forgotten that first you have to learn how to grow stuff? Robert claimed that it wasn't high horticulture, but he knew about plants. Forest gardening requires skill just as conventional gardening does – and probably more of it. Yet many forest gardens were planted by those taking up the trowel for the first time – community groups and permaculture courses, with newly formed friendships and a buzz of optimism. The boring rigour needed for a successful garden was all too easily lost.
Perhaps the whole idea was a tad before its time. This was the era of TV garden makeovers: people wanted purple gravel and cordaline palms. Even now, in a world where grow-your-own and gardening for wildlife are popular pastimes, a cursory glance from a train window reveals a majority of grass and concrete patches – adding to climate change in both their construction and upkeep. A forest garden might be less labour-intensive than a lawn, but its maintenance takes more understanding than starting up a mower. Perhaps it is time for a simplified, popular forest gardening movement. For drawing people in with something simple – some autumn raspberries (no difficult pruning involved), a pot of nasturtiums (edible and easy).
But we mustn’t lose sight of the bigger opportunities forest gardening brings. It's a rare thing for a whole new form of gardening to come along. It requires a shift in attitude, and a set of new skills. Traditional vegetable growing has taken thousands of years to evolve. Plant varieties have been bred, rotation patterns designed, pest control achieved. Who would have thought this was possible looking at the original wild carrots? Forest gardening needs a chance to evolve and to be understood.
Just now in the UK we have enough to eat. It's rewarding to grow our own food – but a crop failure doesn't mean we starve. Historically, it's an unusual situation, a rare opportunity to experiment.
My relationship with forest gardening has been through some tough times – from blissful infatuation, to disillusionment, to acceptance of limitations, and a new appreciation of possibilities. I still use many techniques from my forest gardening experiments - ground covers, mixed plantings, nitrogen fixers and mulches. But it has been a while since I worked on a full forest garden, and I miss it. There's a nice patch next to CAT’s new WISE building that's waiting for a little planting action. So, I'm ready to give it another go – ready for the second round of mistakes.
First... learn about plants
The main components of a forest garden are going to be there for a long time, so it needs to be well designed. Imagine an apple tree growing above redcurrants and fennel, with a ground cover of wild garlic. Each plant has its space and role, and the system is more productive than a monoculture of one crop. Careful design is needed for the plants to benefit each other rather than compete.
We can learn a lot from annual vegetables. In planning a veg patch we carefully think about the needs of each plant over its lifespan. It all happens in one season and a small space, but it teaches the basics of garden design.
The ‘three sisters’ is a native American technique which has recently become more popular in Britain. Sweetcorn, squashes and beans are grown together in one patch with the squash trailing over the ground, the corn growing up vertically through it and the beans twining up the corn. It is a microcosm of a forest garden in time and space. The sweetcorn offers physical support to the beans, the beans fix nitrogen, benefiting the squash and corn, and the squash covers the ground, retaining moisture and preventing soil erosion. However, it's a system which takes some skill in planning. Plant the beans too early and they will weigh down the corn. Plant the squashes too close together and they will out-compete the beans. Plant the sweetcorn too far apart and they will not pollinate each other and you will get no crop.
For more information
- Robert A de J Hart, Forest Gardening, published by Green Books and available from CAT.
- Dave Jacke with Eric Toensmeier, Edible Forest Gardens. American two-volume set exploring design and practice.
- The Agroforestry Research Trust for publications and courses: www.agroforestry.co.uk.
- Plants for a Future, a resource site for edible perennials: www.pfaf.org.
- Tir Penrhos Isaf for permaculture design, advice and courses from forest gardening pioneer Chris Dixon: www.konsk.co.uk.
About the author
Chloe works to show the links between gardening and the wider environment through CAT's display site, courses and publications. She formerly worked for Garden Organic at Yalding Organic Gardens, Kent. She specializes in fruit and wildlife gardening, and is part of the seed-saving movement to preserve our vegetable diversity.