Ten dormant cocoons come in a small cardboard container.

Store the container in a safe spot in the refrigerator until about a week before crops begin to bloom. When the nest site has been cleaned and prepared, secure the box of cocoons to the nest site. As the sun warms the nest site, the mason bees will emerge. Emergence can take hours, or several days. Males emerge first, then the females. Osmia lignaria propinqua. Mason bee cocoons can survive down to -10°C

We sell the nest sites as well but have those in stock regularly.