It is best to plant the seedlings and sow the seeds as soon as possible after regeneration felling to minimise the duration of the sparsely wooded phase and help the forest quickly become a carbon sink. Forest regeneration is easier and more successful if it is carried out before ground vegetation covers the area.
In Finland the planting season is in the spring, when the soil has thawed, and continues until the autumn with the suitable type of seedling. Depending on the tree species, 1,600 to 2,200 seedlings are planted per hectare in the regeneration area. It is important to plant the right tree species in the right environment. Spruce and birch require more nutrients and humidity than pine, which does well in barren and dry environments. Your personal forest specialist can help you choose the right forest species and type of seedling.
Seedlings can also be planted in the autumn
Trees are usually planted in the spring and early summer, but the autumn is also a good time to plant seedlings. A seedling planted in August or September has time to take root before the winter and will start growing quickly when spring arrives. No planting should be done after September, because seedlings will not grow roots so late in the year.
Thanks to the short-day treatment performed at tree nurseries, autumn seedlings have been prepared for the winter in advance and endure autumn frost well. Their growth has been stopped in July by artificially shortening the length of days. Autumn planting is more suitable for spruce in coarse or medium-coarse mineral soils that are not susceptible to frost or do not suffer from excess water. Fine mineral soils or peatlands are unsuitable for autumn planting because of their susceptibility to frost. If you are considering autumn planting, your personal forest specialist can help you decide whether it is suitable for your forest.
The use of elite seeds for pine sowing ensures good tree growth
You can also start a new forest by sowing. Pine sowing is suitable for less fertile sites, where grass is not a threat to seedling growth. In southern and central Finland, we use seed material from 1.5-generation seed orchards, also known as elite seeds, which ensure good tree growth and the best possible technical properties. In the northernmost parts of Finland, we also use seed material collected from forests, because seed material from seed orchards is not available everywhere.
Sowing can start in the spring, once the snow has melted, and continue all the way to midsummer. Pine sowing is usually carried out mechanically in connection with soil preparation, but it can also be done manually in smaller areas.