Before deciding what trees to plant or re-plant, the foresters "3 Rs" are crucial. You need to plant the Right trees in the Right place and for the Right reason. Are the trees being planted with the main objective of timber production or is it landscape, conservation, recreation, sporting, shelter or a combination of these?
Not all trees will prosper - or even grow at all - in just any type of site. Features such as the type of soil, drainage, wind exposure, altitude all have to be considered in selecting the best types of tree to grow in a particular place. What will grow well on a chalky soil will not often thrive on an acid one, trees that do well on wet areas may succumb on dry ones, some trees tolerate salt-laden sea winds but not all, and not all trees grow good commercial timber.
Where nature conservation is a high priority, choosing native tree species of local origin means a different selection of trees would be planted than if growing commercial timber is high on the priority list.
Depending on soil factors and drainage, the site may need preparation. Different tree species are adapted to different conditions - match the two together and the trees are likely to grow successfully; get it wrong and they may never come to much.
Ground preparation may involve some drainage and cultivation and scraping or scarifying the ground or ploughing or mounding the soil.
In larger scale operations, most trees are planted as transplants.
Restocking is planting trees on sites where they have been felled.
In some places and under certain conditions, natural regeneration of seedlings from nearby parent trees happens by accident or design and planting seedlings may not be necessary.
Most seedlings are planted as bare-rooted transplants raised from seed, spending one or two years in seed beds and then being transplanted for a further one to two years before being lifted and planted out in the forest. Transplants are described as 1+1, 2+2, 1+2 etc. depending on the years spent in the seed bed (the first number) and in the transplant lines (the second number). So a 2+2 spent two years in the seed beds and two in the transplant line.
Where the seedlings were left in the seed beds and undercut rather than transplanted, two and three-year-old undercut plants are referred to 1u1 and 1u1u1 in forestry nursery catalogues.
Larger seedling plants are not always the best to use; the biggest is not always best when it comes to seedlings. A healthy fibrous root system is often as important as the green parts seen above ground.
Besides bare-rooted stock, plants are also now raised in small containers or cell-grown nowadays.
Plants may be put in the ground by machine or by hand depending on the situation. Modified spades or planting tubes are used in this back-breaking work.
Spacing is all important. The chosen spacing depends partly on the aims of planting the tree crop. Where timber production is important, the trees are planted fairly close together at as close as 1 metre apart, in lines to form a chequerboard pattern. By planting trees fairly densely, this encourages them to grow straight and upright and provides the forester with more trees from which to select the best ones to grow on as a crop.
Planting on a grid system makes weeding and care simpler in the early years too. If planted at 1 x 1 metres, you need 10,000 trees per hectare; at 1½ x 1½, 4444; at 1 x 2, 5,000; and 2 x 2, 2,500. So a lot of small trees are required to plant new woodland or to restock felled or windblown sites.
On larger areas, trees may need protecting from deer, rabbits or livestock by using fences. They can also be protected individually using tree shelters. They provide a mini greenhouse which enhances tree growth and survival, protects them from grazing animals, makes them easier to spot in long vegetation and protects them if competing vegetation needs spraying.
More: FC Practice Guide 016. "Creating new broadleaved woodland by direct seeding". By Ian Willoughby. (2004)