This spring I am trying to grow the following species from seeds: Ilex verticilata, Cercis canadensis, Betula nigra and Quercus. Here is how I break the seeds dormancy for most native species from Canada.
scarification
The seeds are first soaked in boiling water and then left for 24 hours at room temperature. The ones that float are most likely sterile and are discarded.
stratification
The second step to break the seed’s embryo dormancy is to simulate a winter in the ground. The seeds are mixed with sterilized and moist sand and stored in the refrigerator between 30 and 90 days, essentially until I am ready to sow them.
