Planting a new wood is an exciting project – whether on one's own land or as part of a community project. Trees are the biggest living things on land, and the longest lived. Decisions made now will stand for decades if not centuries, so it's worth taking a great deal of care over the design of a woodland.
Not all places are equally suitable for tree planting, so if you have a choice it's worth giving careful thought to which areas are best for trees and which for other uses. If you're thinking of buying land for tree planting it's impor-tant to survey it carefully first. People have been known to buy land first and find it's unsuitable for tree planting afterwards.
The worst place to plant trees is on land which already has a rich biodiversity. Wildflower-rich grassland is foremost among these. It's a wonderfully diverse ecosystem and over 95% of it has been destroyed in Britain by agricultural intensification over the past 50 years. The few fragments which remain are of priceless value. Sometimes it can be found on steep land which cannot be farmed intensively. The plants growing here cannot survive in shady conditions, and planting trees, or allowing them to regenerate naturally, will lead to a great loss of biodiversity. Your county or urban Wildlife Trust will be happy to give advice on the suitability of your site from a biodiversity point of view.
Compared to garden and farm crops, woodland trees are undemanding, both in terms of soil fertility and of human attention. So the most fertile sites and those closest to home are usually best put to a more intensive use. Woods can give useful shelter. But a narrow shelter belt is more effective than a whole woodland, and will take up less of this high-value land. A wood intended for timber production will need good access for extraction, even in winter when the soil is wet.
Some species of trees are susceptible to spring frosts when they're young, so planting trees in a frost pocket will restrict the choice of species. A very wet site will restrict the choice even more, as only alder and willows will grow well there – and wet areas are likely to be valuable for their existing diversity too. But trees do need moisture, and a very dry site will be difficult both for establishment and growth of trees. Thin soil, a south or south-west facing slope, or exposure to prevailing winds all make for a dry site. On the other hand steep slopes are susceptible to soil erosion, and woodland will protect them better than any other kind of land use.
Which Trees To Plant
The choice must flow from a blend of two main factors: the nature of the site, and the reasons for planting the wood.
Different trees have different tolerances for soil and climate, and it's essential to choose ones which will do well on a particular site if the wood is to thrive. There are a number of books which give advice on this. (See 'Further Reading' at the end of this article.) It can also be valuable to visit local woods to see what is growing there. Be sure that you look at woods with similar soils and microclimates. A dry, windy hilltop will suit different trees from a wet, sheltered valley bottom, even if they are only half a mile apart. Also, look for which trees are really thriving. There's all the difference in the world between mere survival and healthy, productive growth.
Where there is air or soil pollution, or on degraded sites where there is no real soil at all, the choice is especially restricted. Expert advice is advisable on these sites.
Where biodiversity is the main aim, native species should always be used as they support much more wildlife than non-natives. Take care that they are native to the locality, not just to Britain as a whole, and that they come from locally collected seed. However, in urban areas it may be appropriate to include some species which are not native but are characteristic of self-sown urban woodland. A wholly native wood is not a natural feature of the urban landscape, and some non-natives, such as buddleia, can be good for wildlife. A high proportion of shrubs is appropriate in this kind of wood, and as they are small they may be a majority of the plants actually planted.
Where production is an aim the trees need to be carefully chosen for the intended purposes. These may include high quality timber, quick-grown timber, coppice for craft materials, coppice for fuel and so on. It's often worthwhile to include some nurse trees – tough, short-lived trees which give shelter to the higher-value, long-lived trees in the early years and then are removed.
Different species are suited to these different functions, although some can fulfil more than one. Ash, for example, can be grown for timber, or coppiced for craft material and firewood. Non-native trees, including conifers, may be quite appropriate when they can fulfil a specific function which could not be done by natives on that site.
A few hardy edible species, such as damsons, crab apples and brambles can be included on sunny edges. Other fruits are unlikely to succeed in the tough environment of a woodland. Nutting varieties of chestnut, grown as a standard rather than as coppice, can yield well given the right soil and climate. But walnuts and hazelnuts will most probably all be taken by grey squirrels.
A riot of diversity is appropriate for woods where amenity or nature conservation is the main aim, but in a productive wood a simpler mix is easier to manage. Two or three main species plus 5-20% of minor ones may be a good compromise for a productive plantation. The main species must be compatible with each other in terms of speed of growth, shading and shade tolerance.
The mixture of trees may not be uniform over the whole wood. Even the smallest sites may have differences in soil or microclimate between one part and another. Also, you may have multiple aims in planting the wood, and these may be best met by having a productive plantation in one part and a more naturalistic planting in another.
On some sites it may not be necessary to plant at all. Where there are seed parents nearby and the ground vegetation is sufficiently open, natural regeneration may be equally successful. But it may not make a very productive wood unless the seed parents are the right species.
There are generous grants for planting trees in this country, but they can be a mixed blessing. Their main aim is to take land out of agricultural production, so they encourage planting on the best farmland, and exclude edible species. They also favour high forest rather than coppice. Often the strictures of a grant can turn an exciting permaculture design into just another timber plantation. If you can get a grant for what you want to do anyway, that's great. But if you find yourself watering down your design in order to get the grant, or a higher rate of grant, I'd suggest you try and see if there's any way you could manage without it.
Remember, you're setting the scene for a hundred years to come. It's worth getting it right
The Woodland Way – a permaculture approach to sustainable woodland management, Ben Law, Permanent Publications, 2001. Includes a chapter on planting new woods and is available from the Green Shopping Catalogue. Or an intimate account of Ben's yearly cycle of work, his naturally attuned lifestyle and deep emersion in the very fabric of the nature of his woods, The Woodland Year
The Earth Care Manual, Patrick Whitefield, Permanent Publications, Contains species and design information and is available from the Green Shopping Catalogue