With the permission of landowners, seed is taken from Northern Ireland's remaining native woodlands. Between June and December, volunteers collect different types of seed as they ripen. Some types of seed are picked from the tree directly; other types are collected from the ground.
Individual seed types are processed differently. For example, seeds in berries are separated from the flesh. This process involves mashing the fruit to a pulp and sieving the good seed away from the skin and flesh of the fruit. This also helps to remove empty seeds. Seeds in cones need to be dried out to allow the seed to fall out.
Only acorns are planted straight away. All the other types of seeds that we grow exhibit some kind of dormancy. To break dormancy, seed is pre-treated (sometimes called "stratification") for between 4 weeks and 18 months depending on the level of dormancy.
Seedbeds and transplant beds are prepared during the summer months in ground previously occupied by trees. This ground is ploughed, manured, rotovated and turned into new beds by hand. Horticultural grit is also added, if necessary, to improve drainage.
Most seeds are sown by broadcasting after carefully calculating germination rates to ensure optimum seedling density. Too close together and the young trees won't grow very well. Too far apart and valuable space is wasted.
Acorns are sown in lines so that the roots of the oak trees can be undercut with a spade during their second year of growth. This ensures excellent root development and reduces the shock of transplanting. Most other trees are lifted during the winter, root-pruned (to allow a good, fibrous root system to develop) and transplanted with more space to grow.
Some trees, such as willow, grow from pegs cut from the parent plant. These pegs are cut to approximately six inches (15cm) in length. When they are planted they rapidly grow a new root and branch system.
Normally after either one or two years, the young trees are lifted, graded into different sizes, bundled and heeled-in (roots stored in sand) until ready for transport to their new homes.