How to Make a Plant Collection
Specimens that are well mounted using archival materials will last essentially forever, but only if protected from "agents of destruction" such as molds, light, and insects. They should be stored in a tightly-sealed box or cabinet. No pesticides need be used if no insects can get into this space.
Insects can be killed by freezing the specimens (after the plants are dried, but either before or after mounting) at a temperature of -10° F. for three days or longer, preferably in a freezer that is not self-defrosting (since these have cycles of warm temperatures). Specimens should be placed in a plastic bag first, and left in the bag until they reach room temperature after coming out of the freezer. Everything should be frozen before being placed in your storage space, and if an infestation is found, everything should be removed and frozen, and the space thoroughly cleaned before replacing the specimens.
The specimens of Calochortus albus pictured at right were collected in 1881.