4 Week Cold Stratification/Prechill
For most Alders, Birches, Cedars, Larch, Pines and Spruces, Redwoods and Hemlocks
For most Alders, Birches, Cedars, Larch, Pines and Spruces, Redwoods and Hemlocks
Recommended for the following species:
Italian Alder (alnus cordata)
Common Alder (alnus glutinosa) Grey Alder (alnus incana) Himalayan Birch (betula utilis jacquemontii) River Birch (betula nigra) Silver Birch (betula pendula) Downy Birch (betula pubescens) California Incense Cedar (calocedrus decurrens) Atlas Cedar (cedrus atlantica) Deodar Cedar (cedrus deodara) Cedar of Lebanon (cedrus libani) Lawson's Cypress (chamaecyparis lawsoniana) Japanese Cedar (cryptomeria japonica) China Fir (cunninghamia lanceolata) Chinese Weeping Cypress (cupressus funebris) Monterey Cypress (cupressus macrocarpa) Mediterranean Cypress (cupressus sempervirens) Italian Cypress (cupressus sempervirens 'stricta') European Larch (larix decidua) Dahurian Larch (larix gmelinii) Japanese Larch (larix kaempferi) Norway Spruce (picea abies) Brewers Spruce (picea breweriana) Qinghai Spruce (picea crassifolia) Engelmann Spruce (picea engelmannii) White Spruce (picea glauca) Jezo Spruce (picea jezoensis) Lijiang Spruce (picea likiangensis) Meyer's Spruce (picea meyeri) |
Colorado Blue Spruce (picea pungens glauca)
Sitka Spruce (picea sitchensis) Wilson Spruce (picea wilsonii) Chinese White Pine (pinus armandii) Turkish Pine (pinus brutia) Lacebark Pine (pinus bungeana) Lodgepole Pine (pinus contorta) Japanese Red Pine (pinus densiflora) Slash Pine (pinus elliottii) Aleppo Pine (pinus halepensis) Bosnian Pine (pinus heldreichii) Masson's Pine (pinus massoniana) Mountain Pine (pinus mugo) Dwarf Mountain Pine (pinus mugo pumilio) Chinese Red Pine (pinus tabuliformis) Japanese Black Pine (pinus thunbergii) Bhutan pine (pinus wallichiana) Yunnan Pine (pinus yunnanensis) Douglas Fir (pseudotsuga menziesii) Blue Douglas Fir (pseudotsuga menziesii 'glauca' Giant Redwood (sequoiadendron giganteum) Coast Redwood (sequoia sempervirens) Northern White Cedar (thuja occidentalis) Chinese Arborvitae (thuja orientalis) Western Red Cedar (thuja plicata) Eastern Hemlock (tsuga canadensis) Western hemlock (tsuga heterophylla) Mountain Hemlock (tsuga mertensiana) |
All of these seeds are relatively easy to germinate and grow. The dormancy within the seed is short and easily broken and reasonable success can be expected even when seeds are sown without any form of pre-treatment. The benefit of a short period of pre-treatment is that a greater percentage of seeds will germinate and the germination of the seedlings will be synchronized with most seedlings germinating within a few days of each other.
Soak the seeds in water for 24 hours. Fully drain away all of the water and place the seeds in a zip-lock freezer bag. Place the seeds in the fridge, it is important that during this period that the seeds do not dry out or are waterlogged otherwise the pre-treatment will be ineffective.
It is important to keep checking the seeds every week or so to make sure that they are not drying out. You could also at the start of treatment incorporate a little damp vermiculite or perlite, this helps to keep the seeds moist but not waterlogged.
After around 4 weeks under these conditions the seeds are ready to be sown.
Seeds should be sown into containers filled with a good quality general potting compost. 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 are sowing in plug trays, sow 2 or 3 seeds per cell.
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 should begin within a 10-14 days of sowing.
Developing seedlings should be fine in full sun, keep them well watered and free of competing weeds.
Growth will accelerate in the second and subsequent years and the developing young trees should be re-potted as necessary preferably during the dormant season.
Soak the seeds in water for 24 hours. Fully drain away all of the water and place the seeds in a zip-lock freezer bag. Place the seeds in the fridge, it is important that during this period that the seeds do not dry out or are waterlogged otherwise the pre-treatment will be ineffective.
It is important to keep checking the seeds every week or so to make sure that they are not drying out. You could also at the start of treatment incorporate a little damp vermiculite or perlite, this helps to keep the seeds moist but not waterlogged.
After around 4 weeks under these conditions the seeds are ready to be sown.
Seeds should be sown into containers filled with a good quality general potting compost. 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 are sowing in plug trays, sow 2 or 3 seeds per cell.
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 should begin within a 10-14 days of sowing.
Developing seedlings should be fine in full sun, keep them well watered and free of competing weeds.
Growth will accelerate in the second and subsequent years and the developing young trees should be re-potted as necessary preferably during the dormant season.