One of our projects is to start hundreds of trees from seed. We're going to use those seedlings to try and create a new small forest in the place of another one that was removed some 80 years ago for agriculture.
So we use winter time to collect tree seeds of the two species that grow natively and well - black locust and ash.
That is a bucket of ash seeds on just 2 sqm in our yard, where we have an old ash tree.
And when we prune the black locust we grow as coppice in our new orchard, we keep the tops with the seed pods. Seeds have to be separated and then soaked in hot water before planting.
That is a good game for the kids, taking the seeds out! They like to eat the flowers of the black locust so they enjoy the idea of planting more of it.