Basswood/American Linden is a gorgeous shade tree with many practical uses. Honey bees love them and basswood honey is some of the lightest/finest honey. Tea can also be made from the fragrant blossoms and the young leaves are edible.
Seeds will germinate best if planted right away (directly in soil) or if put into soil filled container and stored outdoors until spring. We “winter sow” all of our tree seeds by placing them in a container of sand/potting soil mix and then leave them out in our Minnesota winters until spring. When they have froze/thawed, cooled/warmed, wetted/dried enough that the seed breaks free of the capsule, the tree sprouts on its own when it is ready. It is important to cover the pot with some type of permeable lid – I use window screen. This allows moisture/air to enter but keeps out birds and rodents. If you can not plant right away, then store in a cool/dry place until spring.