storing seed, storing pollen
Wed, 01 Sep 2004 15:12:05 PDT

I've enjoyed the discussions on seed collecting.  I try to stay away from 
plastic due to the high humidity this area--but will use anything in an 
emergency.  I often fold bits of muslin around stems and secure with a twist tie.  I 
really like the idea of the tea bags.

But, I wonder how folks store their seeds.  Some bulb seeds are not orthodox, 
and so long-term storage is out of the question.  But, most bulb species have 
orthodox seeds and, in theory, should behave according to the various 
equations describing seed life vs. varying moisture contents and storage 

I like to dry orthodox seeds indoors, in an air conditioned room for as long 
as they need, a week or 4 weeks.  I never dry them outdoors because they might 
not dry, and because I don't want them getting warmer than about 80-85 F 
while they are drying.

Then, I put them into paper envelopes and label them and put the envelopes 
into airtight plastic food containers with Drierite (color indicating type).  I 
put in about an inch of Drierite in a 6 x 6 inch plastic container, anywhere 
from 2 to 5 inches tall.   I leave the seeds (in their envelopes inside the 
plastic box) at room temperature for a week or so; if the Drierite changes to 
pink I replace the Drierite.  I like the color indicating Drierite, blue = good 
and pink = "time to change."  You can use white Drierite too and it is less 

Once the Drierite seems to have taken up all the water it can, I transfer the 
seed envelopes to a new plastic container with more Drierite and put them in 
the kitchen refrigerator.  In theory I could freeze them for even better 
longevity.  But, by drying them well and cooling them to about 38 F (3-4 C) they 
should last a lot of years--I'm guessing 10-20 years easily.  

In theory, for every 1% of moisture content that you can remove from a seed 
(say from 11% water to 10% water), you can double their storage life.  Also, 
for each 5 degrees Celsius (9 degrees F) that you lower the storage temperature, 
you can double their life in storage.  

The effect is multiplicative so if you can take seeds from 15% moisture 
content (5 doublings) and store them at 38 F instead of room temperature (about 4 
doublings), you can increase their storage live by 20-fold.  If you freeze 
them, it should be all the better as long as they are dry enough.  

Of course, if seeds are going to last a year or two anyway, is there any need 
to store them so they might last 10 or 20 (or 40 years)?  I guess that 
depends upon you.  I'm forever gathering way too many seeds and drying them and 
storing them.  Then, I have some on hand when a trade comes up.  Similarly, 
sometimes I like to collect native shrub seeds and send them out to all who want 
them in exchange for SASE---you meet a lot of nice folks that way.  If I run out 
of refrigerator space, I'll just keep them at room temperature--they still 
should last a number of years as long as they are dry.  


Conroe Joe

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