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Q. How can I start my own pine trees from seed?
A. Starting your own conifers can be a lot of fun and can allow you to keep a special or uniquely sell-adapted tree variety going. You will need to experiment a little and keep careful notes to see what works.
Your first job is going to be to locate cones from the tree you wish to propagate. Make sure the tree is growing in conditions similar to where the seedlings will be planted – in other words, do not take a tree growing high in the Sierras and propagate seedlings to be planted in the Bay area and vise-versa. Check whether or not the cones from the tree you have selected are serotinous, which means they need fire to open.
You will need to check the tree regularly for cones, beginning in early summer. Collect the seeds when they are mature, but prior to their release from the cones, which is easiest to tell if you cut a cone open. The seeds should be plump, with the white material surrounding the embryo firm to the touch. If possible, cones should be collected from the tree prior to falling, but fallen cones can be collected if you can get to them before the squirrels do. Place the cones in labeled brown paper or burlap bag and place in a cool, dry, well–ventilated area to dry for several days. Check the bags regularly to make sure that the cones are not getting moldy.
Once the cones have dried, remove the seeds and clean them with screening that allows the seeds through but not the woody material. Place the cleaned seeds on shallow trays to dry for several more weeks before placing them in an airtight container with a small amount of desiccant.
The seeds may need to be stratified to duplicate the cold
winter dormancy period they experience in nature. This can be accomplished by
placing the closed container in the freezer, checking regularly for those
killer molds. After several weeks, rinse them well and soak the seeds in
several changes of water for 24 hours. Do a
germination test by placing some of the seeds in damp paper towels and in a
clean plastic bag at room temperature. The seeds should germinate in 5-30 days.
If not, they need to be cold stratified a bit longer. Plant seeds in containers
that will allow roots to develop and water regularly