Common Alder (alnus glutinosa)
0.5 gram (approx 312 seeds) £1.25
1 gram (approx 625 seeds) £1.75
2 grams (approx 1250 seeds) £2.30
5 grams (approx 3125 seeds) £4.75
10 grams (approx 6250 seeds) £7.40
25 grams (approx 15625 seeds) £13.80
50 grams (approx 31250 seeds) £24.50
Although these seeds are from a good source they are not approved for forestry use
Use the drop down button below to select the seed quantity
It prefers a heavy soil and a damp situation and can tolerate prolonged submergence of its roots and periods with standing water to 30cm deep. It needs to be planted in an open situation with good light. It will not grow when planted in the shade.
It is important as coppice tree on wet and marshy ground. The alder is capable of enduring clipping as well as coastal conditions. The tree may be cultivated as a windbreak. It adapts to the conditions fast and the young trees also develop rapidly, almost growing about one meter or more in a year. The alder is an outstanding pioneer species for reinstating forestland or abandoned farmland and other difficult soils that do not support vegetation easily such as reclaimed sites . Its rapid growth and the light shade that it casts provide good conditions to establish more exacting forest trees. Its roots contain large swollen nodules that contain bacteria that 'fix' atmospheric nitrogen and makes it available in a form that the tree and some other plants growing nearby can use .
For germination the seeds require a period of moist pre-chilling also known as stratification before the seeds should be sown, this takes around 6 weeks in the fridge.
Germination Sowing and After Care Information for
Common Alder (alnus glutinosa)
After between 4 and 6 weeks under these conditions the seeds are ready to be sown. In general, many seeds will fail to germinate unless treated in this way, simply sowing untreated seeds in compost at room temperature will not break down the dormancy and germination will be disappointing. You can also choose to mix the seed with moistened vermiculite, fine perlite or sand. These help to stop the seeds from clumping together and allow more between the seeds.
Fill your chosen container with a good quality general potting compost and firm it down well. Suitable containers could be plant pots, seed trays or plug trays or even improvised containers with drainage holes. Firm the compost gently and sow the seeds on the surface, if you have pretreated your seeds without any vermiculite/perlite etc. the seeds will be difficult to separate from each other. If you add a little dry sand at this point and mix thoroughly you will find that the sand separates the seed and makes it much easier to sow. Cover the seeds with a couple of millimeters of vermiculite or failing that a fine layer of sieved compost. Follow with a gentle watering and keep them at room temperature.
Germination will begin from a few weeks following sowing. The seedlings are very small and delicate, they need to be kept out of hot sun until the first true leaves emerge. Shading and a moist seedbed are very important for successful germination. Seedling growth can be very rapid and in their first growing season the seedlings can grow to heights of between 20-50cm. It is preferable to produce shorter, stocky, well branched seedlings rather than long leggy ones. High quality seedlings like these can only be grown if the sowing density is relatively low.
Keep the seedlings well watered and free from competing weeds. Growth will accelerate in the second and subsequent years and the developing young trees should be planted in their permanent position usually by the end of their second year. Large trees of these species do not transplant well and should only be moved during the dormant season.