Book of the Week
Friday, October 14, 2011
How To Make a Forest Garden, part one
Forest gardening is a type of permaculture in which trees and other plants are grown for food, fuel, fiber, medicine and other resources in a method that mimics a forest ecosystem. The advantages of forest gardening include extreme productivity, relatively low maintenance requirements, and the fact that it does not require inputs of artificial fertilizers, pesticides or other chemicals. Forest gardening can be done by anyone with even a small plot of land. See my Introduction to Forest Gardening article for more on the general concept.
How To Make a Forest Garden, part one
Once started, a forest garden can be relatively low-maintenance, but it does take some planning to get there. Your approach to the design of your particular forest garden will be affected by the current state of the land you are using:
1- A bare plot of land, with no trees or shrubs.
2- A plot of land that has some scattered trees and shrubs.
3- A plot of land that is already heavily wooded.
All three offer a different set of challenges and opportunities.
Bare land (or grassland) allows you to build your forest garden entirely your way - planting only those trees, shrubs and other plants that you want, where you want. A disadvantage is that, with no trees and shrubs already present, you will need to plant more than you would otherwise have to. You will also have to wait until what you plant matures before harvesting any food.
Land that already has some trees and shrubs scattered about is what most people will have. Chances are the backyard or other area you want to turn into a forest garden will already have some trees and shrubs at or near maturity. You will have to decide which ones are worth keeping, and design your forest garden around them. This means that some of the species in your forest garden, as well as some of its layout, is already decided for you.
Existing trees and shrubs that you definitely don't want in your forest garden can be cut down and turned into lumber, firewood or mulch. One word of caution about cutting down trees - you can't change your mind after cutting one down. It takes a long time to grow a new one in its place, so make absolutely certain you don't want it before taking a chainsaw to it.
Heavily wooded or forested land can also be turned into a forest garden. You will need to clear out sections to make room for new plantings, and it will take some time for you to identify all the already present trees and shrubs you want and don't want. Heavily wooded areas require the most careful planning, but you will have the least time to wait for it to mature. Remember that the trees, shrubs and other plants that are removed can be turned into useful items such as lumber, firewood and mulch.
The particular land you want to turn into a forest garden may also present some other challenges. You may be dealing with land that is arid or desert, especially narrow strips of land (prefect for hedgerows and verges), pre-existing orchards, or other unusual situations. These situations offer some unique challenges and opportunities which will be explored in future articles.
Canopy or Overstory Layer
The first element to consider in designing your forest garden is the canopy layer. The canopy layer is made up of the tallest fruit and nut trees and will provide you, and wildlife, with food. Fallen and dead branches can be turned into firewood or mulch. Fallen leaves can be turned into mulch or compost. The canopy will also provide nesting areas and shelter for birds, insects and other wildlife.
Here is a very short list of possible species to include in your canopy:
Tree - Scientific Name - Common Uses
Beech - Fagus grandifolia - Nuts
Butternut - Juglans cinerea - Nuts
Hickory - Carya sp. - Nuts
Monkey-puzzle Tree - Araucaria araucana - Seeds
Pecan - Carya illinoinensis - Nuts
Pines - Various species - Nuts, Windbreaks
Sugar Maple - Acer saccharum - Syrup
Walnut - Juglans sp. - Nuts
White Oak - Quercus alba - Nuts
How to decide what trees?
First, consider how many canopy trees you have room for on your land. As a general rule of thumb, Robert Hart recommends planting canopy trees 20 feet apart. You'll need to know the size of the plot of land your turning into a forest garden, and then do some math to figure out how many will fit in your garden. If you only have a small plot of land, then you may plant only one canopy tree, or skip the canopy layer entirely and plant understory trees instead.
In deciding what to plant, your personal preferences should be considered. If you hate black walnuts, then don't plant black walnuts. If you love pecans, then you probably should consider planting pecans.
Other important considerations are what trees grow well in your region, your climate and your soil. The growth rate of your trees should also be taken into account. Find out your plant hardiness zone if you don't already know it (see below). When planting trees, don't forget to consider how they will spread as they mature. Avoid planting too near buildings and power lines. Information on the height and spread of mature trees is widely available in various books and websites (see below).
Consider planting not only for food, but other benefits as well, such as windbreaks or soil improvement through nitrogen fixing.
The understory is the second tallest layer of a forest garden next to the canopy. The understory is typically made up of smaller trees such as fruit trees, particularly those grown on dwarf root stock. These trees will be planted in between the canopy trees.
As with the canopy trees, you must consider several factors before deciding what trees to plant in the understory. What trees grow well in your region, your climate and your soil will determine what trees you'll be able to choose from and, of course, your personal preferences should be considered.
On a personal note, I would encourage people to plant at least a few of the less common fruit trees if they have room. Consider planting a couple pawpaw trees; the fruit are extremely nutritious. Or consider planting a couple of persimmon trees; not only is its fruit delicious, but the leaves can be used to make a tea that is high in vitamin C.
Here is a very short list of trees that could be planted in your understory:
Tree - Scientific Name - Uses
Almond - Prunus dulcis - Nuts
Apple - Malus pumila - Fruit
Cherry - Prunus sp. - Fruit
Fig - Ficus carica - Fruit
Kentucky Coffee Tree - Gymnocladus dioica - Nitrogen Fixer
Pawpaw - Asimina triloba - Fruit
Peach - Prunus persica - Fruit
Pear - Pyrus communis - Fruit
Persimmon - Diospyros sp. - Fruit, Leaves
Witch Hazel - Hamamelis virginiana - Medicinal
To find your plant hardiness zone
(click on your country or region)
UK & Ireland
Rest of Europe
Books on Forest Gardening
Forest Gardening: Cultivating an Edible Landscape - A classic by the Father of modern forest gardening, Robert Hart. A detailed explanation of the forest garden model, including lists of recommended plants broken down by climate type. It does get a bit philosophical at times, but is useful for both the beginner and the expert.
Edible Forest Gardens (2 volume set) - This two volume set is the best and most detailed explanation of forest gardening that I know of. Includes an extensive matrix of edible and useful plants. HIGHLY RECOMMENDED
How to Make a Forest Garden - This book by Patrick Whitefield covers the basics of forest gardening, including core principles, design and how to choose plants. Also includes over details of over 100 suggested plants for a forest garden.
Plant and Tree Databases
Arbor Day Foundation - In the USA, the Arbor Day Foundation's Tree Wizard is a very useful database of trees, including fruit and nut trees. You can look up trees by zip code, hardiness zones, types, height, spread, soil type, sun exposure and growth rate.
Plants For A Future - Plants for a Future is a fantastic website with lots of information for forest gardening, including extensive databases of trees & other plants.
Hedging Plant Index - Part of the UK website of Ashridge Trees, so the information is particularly useful for those living in the UK.
How To Make a Forest Garden, part two
Part two of this series will examine the shrub layer, the herbaceous layer, and other layers, as well as organizations of interest to those wanting to practice forest gardening. Be sure not to miss it or any of my other articles by signing up for free updates by email or following me on Twitter (see right-side column for further information).