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.
Click below to see a 2010 short video (13 mins) about our forest garden
at Dartington.
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 millennia 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).
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
