Walnut trees flower in October and November. The flowers are wind pollinated so we don't have to rely on the bees. When the trees are in full leaf the leaves give a wonderful clean aroma. The nuts grow inside a green husk and are fully formed by the end of December, when they can be harvested before the shells harden, to make Nocino (green walnut wine) and pickled walnuts. At the end of March, the husks begin to split and dry, revealing the walnuts in their shells.
We harvest the nuts mostly by hand, washing off any remaining green husks then drying the nuts using room temperature air in bins. After drying they will keep for over a year if stored in a cool dry place. They are sorted by size before packaging and labelling to sell in-shell. Some will be cracked for kernel sales and pressing into oil and walnut flour.
See here the many ways that walnuts can be used - fresh, green, dried, black, activated.