Propagation of native trees and shrubs from seed is not easy for all species, but by following the advice given below it is possible to grow your own planting stock from locally collected seed. General experience with growing garden plants from seed is useful, although tree and shrub seed requires some different techniques.
Note the following:
- The main benefit in growing your own plants from seed is that you can collect from local native trees and shrubs, which if growing in a similar soil and position to the planting site should be well adapted to local conditions. Very old trees or those from old woods or hedgerows may be of a local genetic strain which it is worth maintaining.
- Growing your own trees from local seed is a worthwhile activity which can involve the community in many ways, and which not only produces trees, but has other benefits for the people involved. growing trees from seed is an excellent project for schools, which has links with the national curriculum, as well as with wider environmental awareness and practical skills. Many schools have suitable sites for growing and planting, as well as the continuity required to maintain a project for a few years.
- A small, well-run nursery from which young transplants are produced for planting out may be worthwhile on economic grounds, as young trees can be produced very cheaply. On the other hand, commercial nurseries have the expertise and economies of scale to produce good quality stock at reasonable prices, and normally are able to give buyers the flexibility to choose what they want, when they want it. In your own nursery your stock will be limited by the seed which you are able to collect and successfully germinate, and grow on for two years. Trees of particular species do not produce seed every year.
- Local or community tree nurseries are likely to be most successful if they are set up in response to a particular need for planting in the following three or four years. Alternatively, they may be part of a large project where trees are to be planted each season over many years. The less successful community nurseries are those set up without a planned planting site for the stock produced, and where the temptation is then to keep the young trees for too long in the nursery. Record keeping is an important part of running a community nursery, as different people may be involved in running it.
- The Forest Reproductive Material Regulations 1977 control the marketing of reproductive material (seeds, plants and parts of plants) of species used for timber production, which includes five native species. These Regulations only apply to the marketing of reproductive material, and do not apply where planters collect and raise planting material for their own use. Since 1999, a voluntary system has been introduced which covers the sourcing, production and use of all native tree and shrub species throughout Britain. For details see the Forestry Commission Practice Note Using Local Stock for Planting Native Trees and Shrubs (August 1999), which should be consulted by all growers and planters of native stock, both professional and voluntary. It contains valuable guidance on the production and use of local stock of native trees and shrubs, including the map of local seed zones, the native species appropriate to each zone, and advice on seed collection.
There have been many technological advances in the production and establishment of trees from seed. These make it easier, for the grower, both professional and amateur, to successfully produce and plant trees. For most species, this means that young trees can be planted out in their final sites within a period of about 2 years from the time the seed is collected. Short production times have obvious advantages for commercial growers, but for voluntary groups they are also appropriate. The shorter the time the young trees are in the nursery, the fewer the problems with control of root growth, disease and other factors, and the sooner the plants will be where you want them! Techniques include the following:
- Temperature treatment of seed, to encourage quick and even germination.
- Polytunnels and fleece, which give protection for young seedling trees, and allow the production of trees on nursery sites which might otherwise be too exposed or cold.
- Plastic netting, to keep birds off outdoor seedbeds.
- The use of plastic cells or pots for growing trees from seed until planting out.
- Plastic sacks for the safe transport and storage of young bare-root trees.
- The use of treeshelters and guards after planting out to enhance the growth of young trees, and to give protection from browsing animals.
- The use of herbicides or sheet mulches to remove weed growth around establishing trees. Herbicides or sheet mulches are a more efficient means of overcoming weed competition than the use of larger planting stock.