SEED VIABILITY

Jane McGary janemcgary@earthlink.net
Sun, 27 Nov 2016 12:04:19 PST
In recent years I've had quite a bit of experience sowing old, indeed 
very old, seeds. Most had been stored in air-tight containers (e.g., 
glass jars) in refrigerators. It was surprising to see what germinated, 
although not all seedlings survived for more than a few months (perhaps 
because of the age of the cellular components). There were even some 
startling results, such as a single Celmisia from a packet more than 10 
years old (it's still alive 2 1/2 years later, and this is the first 
time I've ever germinated a single one, even from fresh seeds I 
collected myself).

People, including myself, who received seeds from the dispersal of a 
very large seed bank accumulated over more than 20 years by Betty Lowry 
of the Seattle area, have reported somewhat anecdotally on their results 
for an article that is planned for eventual publication in the NARGS 
Rock Garden Quarterly. I have also received long-stored seed from Gene 
Mirro and Ron Ratko.

In general, species from particularly arid regions tend to have seeds 
with long viability, as could be predicted. Among monocots, Calochortus 
and the Themidaceae seem to do this. In proper storage conditions, 
Lilium seeds can have very long viability (and I'd guess this also 
applies to Tulipa).

The literature on seed germination tends to make doctrinaire statements 
about viability, and my personal experience makes me doubt some of 
those. That experience also misled me into thinking, for instance, that 
Fritillaria seed can't be expected to germinate after long storage -- 
yet I got very good germination of F. conica (a desirable species) from 
the Lowry hoard. You will read that certain genera must be fresh to 
germinate, but observation tells us that within a genus there can be 
both short- and extended-viability species; examples are Anemone and 
Erythronium. Some authors write that all the Ranunculaceae are 
short-viability, but there are definitely exceptions; for instance, I've 
raised several Delphinium species from stored seed.

The conclusion I'd offer is that you should sow any seeds you have, 
perhaps retaining a portion of those that are especially rare and 
desirable for later use -- or sharing with other good growers. Indeed, 
sharing seeds with others who may have different growing conditions or 
skills is the best way to ensure that good plants remain in cultivation. 
Thus, I'm glad I sent part of my share of the Lowry seeds to Bob Nold in 
Denver, Colorado, who was able to work successfully with some steppe 
species I couldn't manage here in the Pacific Northwest.

Jane McGary

Portland, Oregon, USA



On 11/27/2016 11:21 AM, Sylvia Sykora wrote:
> In reviewing my seed collection for winter sowing I find myself with packets of seed, many dated more than two or three years ago.  Does anyone know of a list by genera, at least, of viability times for stored seed?  I know this is not a subject with hard and fast rules, but even some general guide lines would be useful and save time and energy sowing seed that's just too old to germinate.
>
> Thank you.
>
> Sylvia Sykora
> SF Bay Area
>




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