I collect the pollen as anthers, soon after anthesis (when the anther opens and displays the free pollen). Remove the anther with its pollen from the filament (stem) and place it in a suitable container. I use tweezers/forceps to grasp the stamen by the filament and break it off.
For more on anthers, stamens, and flower anatomy:
The anther + pollen must be dried before it is frozen. If your climate is such that your ambient relative humidity is low, you can dry in air. Mine is not, and I have a drying chamber. Any large container that can be closed air-tight would work. Use a drying agent. Many find silica gel drying agent (the "blue crystals") easiest to find. I buy Drierite with blue indicator from Daigger scientific supply co. at: http://www.daigger.com/ as
Drierite™ Desiccant
Anhydrous calcium sulfate absorbs 14% its own weight in water. Regenerates with heat and can be reused again and again. (Spread in layer one granule deep and heat at 425°F for 1 hour). Nonpoisonous and noncorrosive. Indicating Drierite changes color from blue to pink when saturated and needs regeneration.
Part #EF10298BA, case of 12 bottles (1 lb. each), #6 mesh, for ca. $100
Containers: I store anthers in 1.5 mL (milliliter) polypropylene microcentrifuge tubes with caps. I dry the anther/pollen in the open tubes, then cap them. Tubes are grouped in zip-top plastic bags for convenience and stored in the freezer.
Pollen Viability: A lot of this is hearsay and word of mouth. The numbers apply to thoroughly dried pollen in the freezer.
When using frozen pollen, allow the tube to warm to room temperature before opening it. Apply the pollen to the stigma using a fine camels-hair artists' brush.
Viability of stored pollen depends on dryness and temperature. The drier the pollen is before you freeze it, the longer it will stay viable in the freezer. The colder the storage temperature, the longer the viability is preserved. I.e., the fridge is good for a week or two or three (at most); room temperature is good for a few days at most.
We find we have to use forceps or tweezers to handle the anthers, once they are remomved from the stamen. In addition, it is easier to remove a stamen from a flower using forceps. Fat finger tips tend to spread pollen everywhere, losing most of that which was initially on the anther.
Jim Shields
For information about this account, contact:
James E. Shields, jim@shieldsgardens.com
Last revised: 14 November 2004
& Copyright 2004 by James E. Shields. All rights reserved.