I have a couple dozen Gingko biloba seeds from various trees in Vancouvber WA. I've planted more than I can handle if they all grow. Happy to share the remaining seeds.

I've had good luck planting gingko seeds outside in the fall, in a sheltered, labeled, garden spot. They usually sprout in mid spring. I think the seeds need cold moist conditions through the winter to stratify.

They can be used for trees. They might also make a unique hedge. It takes some time before they reach good size. In my yard I have a 15 year old seed-grown gingko that is about 20 feet tall, and other 15 year old ginkgo that is about 8 feet tall. The difference is the taller one is in a richer soil and well watered, and the smaller one was in a clay soil without good watering.

The one warning is there is a 50% chance your tree will be female. The female trees start dropping punguent fruits at about 25 years old. Some people don't like those. I don't mind at all. The seeds are used in some traditional Chinese food but have to be specially cooked first in order to be safe. So the female tree is a potential exotic food source. If male, there are no fruits.

The pic is my 15 year old backyard seed-grown ginkgo tree, taken about 2 weeks ago.