Forest Gardens
FOREST GARDENING - by Toby Hemenway
On my ramblings around the country last summer, I ran across a few examples of a gardening method I'd only read about, called forest gardening. It's a multi-layered style of garden, very different from the (relatively) orderly rows and beds seen in most yards. Forest gardens are based on the observation that natural forests rarely contain just a single layer of plants. Forest gardens stack vegetation in as many as seven tiers, depending on how intensively the gardener wants to cram things in.
Layer number one, on top, is the canopy, with big trees like standard apples and pears, walnuts, and the like. Below that and in the openings go the under story, with semi-dwarf fruit trees, filberts, flowering crabapple and cherries, and other trees of medium height. Underneath this is the shrub layer, filled with ornamental bushes and small fruits like raspberries, gooseberries, and blueberries. Next comes the herb layer, a stratum of perennial vegetables and herbs. Undergirding all this is the ground layer, which holds trailing plants like strawberries and other earth-huggers. There are still two more layers to go: Layer number six is for root crops, including Jerusalem artichokes, potatoes, shallots, etc. The seventh and final layer is vertical: Climbers such as grapes, kiwifruit, and ornamental vines. If all this seems overwhelming, you can cut back to two or three layers.
Obviously, this kind of garden looks very different from a conventional one. The forest gardens I saw in Colorado, New Mexico, and the San Juan Islands were a little difficult to find my way around in at first. But quickly I got my bearings, and realized just how much low-maintenance food-growing you could pack into a small space.
I wondered whether enough light could get in through all the foliage, but the owners said that just as in a natural woodland, in the spring the herb layer leafs out first, then the shrubs, then the trees, so everything has a chance to grab some sun. The big trees need to be fairly widely spaced and pruned to an open form, or else it's too dark for the plants' fruit and flowers to develop.
These gardens need little maintenance. Except for a few annual plants tucked in here and there, no tilling is required. The garden is self mulching, and once it's established, the deep roots pull nutrients from far underground, so little fertilizer or water is required (though fertilizer will always give things a boost). The diversity of plants means diseases and insect troubles are minimal. And you can mix ornamentals with food plants that is both attractive and productive.
If you're interested in learning more about forest gardens, two good books are: Forest Gardening, by Robert Hart (1991, Green Books), and How to Make a Forest Garden, by Patrick Whitefield (1996, Permanent Publications).
