
A forest garden is a designed agronomic system based on trees, shrubs and
perennial plants. These are mixed in such a way as to mimic the structure of a
natural forest - the most stable and sustainable type of ecosystem in this
climate.
The primary aims for the system are:
-to be biologically sustainable, able to cope with disturbances such as climate
change
-it should be productive, yielding a number (often large) of different products
-it should require low maintenance.
-The crops which are produced will often include fruits, nuts, edible leaves,
spices, medicinal plant products, poles, fibres for tying, basketry materials,
honey, fuelwood, fodder, mulches, game, sap products.
Forest gardens (often called home gardens) have been used for millennial in
tropical regions, where they still often form a major part of the food producing
systems which people rely on, even if they work elsewhere for much of the
time. They may also provide useful sources of extra income. Their use is
intimately linked with prevailing socio-economic conditions. They are usually
small in area, often 0.1-1 hectares (0.25-2.5 acres).
Installing a Forest Garden
In temperate regions, forest gardens are a more recent innovation, many
inspired by Robert Hart’s efforts in Shropshire (UK) over the last 30 years. A
major limiting factor for temperate forest gardens in the amount of sunlight
available to the lower layers of the garden: in tropical regions, the strong light
conditions allow even understorey layers to receive substantial light, whereas
in temperate regions this is not usually the case. To compensate for this,
understorey layers in temperate forest gardens must be chosen very carefully -
there are plenty of plant crops which tolerate shady conditions, but many are
not well known. Many of the more common shrub or perennial crops need
bright conditions, and it may be necessary to design in more open clearings or
glades for such species.
Temperate forest gardens are also usually small in area, from tiny back garden
areas up to a hectare (2.5 acres) in size. While food production and land use
remain the concern of a minority of landowners and businesses, their use is
likely to be limited to ‘alternative’ and organic gardeners and land users.
The key features which contribute to the stability and self-sustaining nature of
this system are:
-the large number of species used, giving great diversity
-the careful inclusion of plants which increase fertility, such as nitrogen fixers
(eg. Alders [Alnus spp], Broom [Cytisus scoparius], Elaeagnus spp, and shrub
lupins [Lupinus arboreus]).
-the use of dynamic accumulators - deep rooting plants which can tap mineral
sources deep in the subsoil and raise them into the topsoil layer where they
become available to other plants, eg. Coltsfoot [Petasites spp], Comfreys
[Symphytum spp], Liquorice [Glycyrrhiza spp], Sorrel (and docks!) [Rumex
spp].
-the use of plants specially chosen for their ability to attract predators of
common pests, eg umbellifers like tansy.
-the use, where possible, of pest and disease resistant varieties, eg. apples.
the increasing role of tree cover and leaf litter which improve nutrient cycling
and drought resistance.
A forest garden is organised in up to seven ‘layers’ . Within these, the
positioning of species depends on many variables, including their requirements
for shelter, light, moisture, good/bad companions, mineral requirements,
pollination, pest-protection, etc. The layers consist of:
Canopy trees - the highest layer of trees. May include species such as
Chestnuts [Castanea spp], Persimmons [Diospyros virginiana], honey locusts
[Gleditsia triacanthos], Strawberry trees [Arbutus spp], Siberian pea trees
[Caragana arborescens] Cornelian cherries [Cornus mas], Azeroles and other
hawthorn family fruits [Crataegus spp], Quinces [Cydonia oblonga], Apples
[Malus spp], Medlars [Mespilus germanica], Mulberries [Morus spp], Plums
[Prunus domestica], Pears [Pyrus communis], highbush cranberries
[Viburnum trilobum].
Small trees and large shrubs, mostly planted between and below the canopy
trees. May includes some of the canopy species on dwarfing rootstocks, and
others such as various bamboos, Serviceberries [Amelanchier spp], Plum yews
[Cephalotaxus spp], Chinkapins [Castanea pumila], Elaeagnus spp, and
Japanese peppers [Zanthoxylum spp]. Others may be trees which will be
coppiced to keep them shrubby, like medicinal Eucalyptus spp, and beech
[Fagus sylvatica] and limes [Tilia spp] with edible leaves.
Shrubs, mostly quite shade tolerant. May include common species like currants
[Ribes spp] and berries [Rubus spp], plus others like chokeberries [Aronia
spp], barberries [Berberis spp], Chinese dogwood [Cornus kousa chinensis],
Oregon grapes [Mahonia spp], New Zealand flax [Phormium tenax] and
Japanese bitter oranges [Poncirus trifoliata].
Herbaceous perennials, several of which are herbs and will also contribute to
the ground cover layer by self-seeding or spreading. These may include
Bellflowers with edible leaves [Campanula spp], Comfreys [Symphytum spp],
Balm [Melissa officinalis], Mints [Mentha spp], Sage [Salvia officinalis], and
Tansy [Tanacetum vulgare].
Ground covers, mostly creeping carpeting plants which will form a living mulch
for the ‘forest floor’. Some may be herbaceous perennials (see above), others
include wild gingers [Asarum spp], cornels [Cornus canadensis], Gaultheria
spp, and carpeting brambles (eg. Rubus calycinoides & R.tricolor).
Climbers and vines. These are generally late additions to the garden, since they
obviously need sturdy trees to climb up. They may include hardy kiwis
[Actinidia spp], and grapes [Vitis spp].
The final ‘layer’ is the root zone or rhizosphere. Any design should take
account of different rooting habits and requirements of different species, even
if root crops are not grown much. Some perennials with useful roots include
liquorice [Glycyrrhiza spp] and the barberries [Berberis spp] whose roots
furnish a good dye and medicinal products. Various beneficial fungi can also be
introduced into this layer.
BENEFITS:
A long-term biologically sustainable system for growing food & other products
for a household
Once established, little work is needed to maintain
DRAWBACKS:
Planting out and establishment usually requires large numbers of plants and
substantial work.
CLEAN UP:
As a forest garden includes many perennial plants, clean up at the end of the
season can be less of a task than in annual flower and vegetable gardens.
Rather than pulling plants up, cut them off at ground level, which disturbs the
soil less. The tops of the plants can then be incorporated into the mulch, or set
aside for compost
Plants for the Forest Garden
Common Name Scientific Name Uses
Canopy
Beech Fagus grandifolia Nuts
Butternut Juglans cinerea Nuts
Shagbark Hickory Carya ovata Nuts
Sugar Maple Acer saccharum Syrup
White Oak Quercus alba Nuts
Understory
Persimmon Diospyros virginiana Fruit
Apple Malus pumila Fruit, flowers
Cornelian Cherry Cornus mas Fruit
Crabapple Malus spp. Fruit, flowers
Hazelnut Corylus spp. Nuts
Coffee Tree Gymnocladus dioica N-fixer
Paw Paw Asimina triloba Fruit, flowers
Pear Pyrus communis Fruit, flowers
Plum Prunus domestica Fruit, flowers
Serviceberry Amelanchier spp. Fruit, flowers
Witch Hazel Hamamelis virginiana Medicinal, flowers
Shrub Layer
Blackberry Rubus occidentalis Fruit, flowers
Currant Ribes sativum Fruit
Elderberry Sambucas nigra Fruit, flowers
False indigo Baptisia australis N-fixer
Gooseberry Ribes uva-crispa Fruit
Raspberry Rubus idaeus Fruit, flowers
Rose Rosa spp. Medicinal, flowers
Siberian Pea Shrub Caragana arborescens N-fixer, flowers
Herbaceous layer
Arugula Eruca vesicaria Edible
Chamomile Chamaemelum nobile Tea, flowers
Chives Allium schoenoprasum Edible
Comfrey Symphytum uplandicum Medicinal, mulch
Cornsalad Valerianella locusta Edible
Dill Anethum graveolens Edible, insectary
Fennel Foeniculum vulgare Edible, insectary
Garlic Allium sativum Edible
Kale Brassica oleracea Edible
Lemon balm Melissa officinalis Tea
Lettuce Latuca sativa Edible
Lovage Levisticum officinale Edible
Mint Mentha spp. Edible
Spinach Tetragonia expansa Edible
Onion Allium cepa Edible
Parsley Petroselinum crispum Edible
Rhubarb Rheum rhabarbarum Edible
Salad burnet Sanguisorba minor Edible
Sorrel Rumex scutatus Edible
Spinach Spinacea oleracea Edible
Stinging Nettle Urtica dioica Edible, mulch
Flowering Ground Covers
Strawberry Fragaria spp. Fruit, flowers
Nasturtium Tropaeolum minus Edible flowers
Violet Viola spp. Edible flowers
Vines
Grape Vitis vinifera Fruit
Hardy Kiwi Actinidia arguta Fruit, flowers
Hops Humulus lupulus Medicinal
Runner Bean Phaseolus coccineus Edible, N-fixer, flowers
Wisteria Wisteria floribunda N-fixer, flowers

