Scottish Rock Garden Club Forum

Seedy Subjects! => Grow From Seed => Topic started by: Kristl Walek on September 19, 2009, 05:04:30 PM

Title: After drying requirement for Draba species
Post by: Kristl Walek on September 19, 2009, 05:04:30 PM
Katherine, from our forum,  sent me some wild collected Draba lasiocarpa earlier this year.

Draba is one of many genera where seed will rarely germinate when fresh.
The length of after-drying required before germination will occur varies from species to species
and is also dependent on how much drying the seed has already received prior to collection.

To show you how dramatic this is: Draba lasiocarpa was tested as follows:

early June, 2009: 0% germination
June 22: 0%
August 15: 5%
September 17: 95%

Title: Re: After drying requirement for Draba species
Post by: Lori S. on September 19, 2009, 05:27:42 PM
Terrific example of what Deno described as "a germination delay mechanism that is destroyed by drying"!
Title: Re: After drying requirement for Draba species
Post by: Rodger Whitlock on September 19, 2009, 05:53:18 PM
Kristl:

I hope you are starting to compile your deep knowledge of seed germination in an organized form with an eye to eventual publication.

What do you think of Norman Deno's efforts in that field?

Incidentally, there are two families where I always hold back sowing seed until the weather has warmed up a little in the spring: Lamiaceae and Asteraceae.
Title: Re: After drying requirement for Draba species
Post by: Kristl Walek on September 19, 2009, 06:45:45 PM
Rodger,
Well yes and no. Official, written records have been kept for 25 years.  The "general"  knowledge is for my own pleasure, for general consumption, and to provide to my seed customers. I am not a person who lives by the "knowledge is power" doctrine.

The lifelong goal is to educate, to dispel erroneous notions about seed and germination and hopefully, to leave something behind.

Where I know I have made the greatest impact in the seed world is in the treatment of ephemeral seed. I was the first to use and promote moist packing of ephemerals and am still (after 20 years) one of the few seedhouses to treat ephmerals in this way. It warms my heart to see an occasional company following suit. Much more work to be done.

The "eventual publication" is more specific---and getting closer to completion. This is my oft-noted book on the native plants of eastern Canada from a sexual propagation perspective (co-authored by my Ontario seed collecting partner Dr. Graham Page).  I am hoping to be able to devote more time to finishing it now that I am reigning in my business and have (hopefully) begun to uncomplicate my life somewhat with my move to Nova Scotia.

In fact, Graham arrives in a weeks' time for us to sit and see where we are at with text, pictures and seed/spore data. We are now into year 3 with the book. 

Title: Re: After drying requirement for Draba species
Post by: Lori S. on September 19, 2009, 06:50:49 PM
Kristl, I always did think you "reigned" in your business - queen of seed houses!  :) 

(Sorry, I can normally resist puns but not this one... "reigned/reined"...  Anyway, as you were...)

Looking forward keenly to the eventual publication.
Title: Re: After drying requirement for Draba species
Post by: Kristl Walek on September 19, 2009, 06:55:55 PM
Norm Deno was the pioneer in making his work publicly accessible. Many of us contributed research to his 3 books. But his work was still time-limited---but very valuable in laying out general principles, and introducing concepts that were not generally known or understood at that time (working with GA-3, germination as a chemical process, etc. etc.). He was the first to raise the "idea" of storage of ephermals in some alternate fashion---and inspired me to take up the banner, in fact.

There are, of course, many other folks who have done important work in this area.

There is no reason to hold off sowing members of the Lamiaceae or Asteraceae (except practical, perhaps). These generally have no germination delay mechanisms.
Title: Re: After drying requirement for Draba species
Post by: Kristl Walek on September 19, 2009, 07:02:37 PM
Kristl, I always did think you "reigned" in your business - queen of seed houses!  :) 

(Sorry, I can normally resist puns but not this one... "reigned/reined"...  Anyway, as you were...)

Looking forward keenly to the eventual publication.


didn't see that one coming, Lori. blush at my end. thanks. 
it's a wonderful thing, indeed, to still love all this mucking around with seed after so many, many years of doing it.
i consider myself most fortunate to have found the thing i love most.
Title: Re: After drying requirement for Draba species
Post by: Rodger Whitlock on September 19, 2009, 07:29:57 PM
There is no reason to hold off sowing members of the Lamiaceae or Asteraceae (except practical, perhaps). These generally have no germination delay mechanisms.

I consider that both families germinate and grow better with a little warmth. Not having a greenhouse and being restricted to sowing out of doors, I don't end up with failed germination when it's raw and wet.

I think this qualifies as a "practical" reason, but I will betcha a box of TimBits that I'm not the only one who gardens with such limitations.
Title: Re: After drying requirement for Draba species
Post by: cohan on September 20, 2009, 09:04:52 PM
re: draba, does this increase in germination rates continue? or has it reached its peak at the september test? what if the seed is left til next spring, and does this observation apply to other brassicaceae?

rodger, we certainly all do have limitations of one sort or another and have to find the work-arounds best for our conditions!
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