How can I grow a ginkgo tree from seed?
According to the American Horticultural Society’s Plant Propagation (DK Publishing, 1999), seeds may be sown in late winter. Gather the ripe fruit of the female tree in mid-autumn, and clean off the pulp. Then wash the seeds with mild soap to remove germination inhibitors, and store the seeds in the refrigerator for 30 to 60 days before sowing outdoors in containers. Here is more information from Plants for a Future:
“Seed: best sown as soon as it is ripe in a cold frame or in a sheltered outdoor bed. The seed requires stratification according to one report whilst another says that stratification is not required and that the seed can be sown in spring but that it must not have been allowed to dry out. Germination is usually good to fair. Prick out the seedlings into individual pots when they are large enough to handle and grow them on in light shade in the greenhouse for their first year. Plant them out into their permanent positions in the following spring and consider giving them some protection from winter cold for their first winter outdoors.”
The Ginkgo Pages website also has useful propagation information.