Penstemon fasciculatus--stratification required?

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Penstemon fasciculatus--stratification required?

I'm excited to try germinating some Penstemon fasciculatus seed I obtained in the seed exchange. Does anyone have experience germinating this Penstemon? Does it require stratification?


Mark McD
Title: Moderator
Joined: 2009-12-14
Mitchell wrote:

I'm excited to try germinating some Penstemon fasciculatus seed I obtained in the seed exchange.  Does anyone have experience germinating this Penstemon?  Does it require stratification?


Hello Donald, welcome to the NARGS Forum!  I have never tried this species, although judging from photos and information seen elsewhere on the forum, it looks like a beauty.  In my experience, seed of most Penstemon species benefit from stratification.

For more information and clues about it's native habitat, see the following two topics with good contributions by Barbara Weintraub and Lori Skulski.

Mark McDonough Massachusetts, USA, near the New Hampshire border USDA Zone 5 antennaria at  

Lori S.
Title: Moderator
Joined: 2009-10-27

Welcome to the forum, Donald! 

Unfortunately, I haven't tried this species, and Dr. Deno has not published data on it in his seed germination publications. 

McDonough wrote:

In my experience, seed of most Penstemon species benefit from stratification.

I agree, from my relatively limited experience... sowing the seed on moistened medium in a pot or flat and then subjecting it to month or 6 weeks in the cold may do the trick (whether the cold be a cold room, refrigerator, or outdoors); you may get germination either in the cold or when it is brought into the warmth.

Allan Bradshaw, of Alplains (an excellent seed resource!), provided a very useful summary of seed starting instructions to the Calgary Rock and Alpine Garden Society, which was published in the newsletter.  In it, his general advice for penstemons was to stratify.

Or if you prefer less fuss in stratifying, you could always just sow the seeds and place them outdoors in fall (or for the remainder of your winter)... this, as described in Bob Nold's Penstemons, is his preferred method of stratification... and who would know better than this penstemon expert!  :)

Hope that's helpful.  Sorry that I have no personal experience with this one - looks like a beauty!

Lori Calgary, Alberta, Canada - Zone 3 -30 C to +30 C (rarely!); elevation ~1130m; annual precipitation ~40 cm

Title: Moderator
Joined: 2009-09-21

Agreement here too.  Dr. Deno has done a lot of testing on other penstemon species, and results are practically across the board.  Some germinate at 40F, some at 70F, some with light, some without light, most don't seem to care about light.  Unfortunately, I can't find any testing or data on any of the species within the section Fasciculus of penstemon (which encompasses P. fasciculatus), except P. kunthii that germinates at 40F and P. pinifolius that germinates at 70F.  So that doesn't help any.  I winter sow a lot of my seeds to stratify them, including penstemon.  

I don't know where you garden, and especially if there isn't sufficient time for a proper cold treatment, be sure to hold the pots over for another year if they don't sprout.  I had zero germination on two species of penstemon one year after winter sowing (one was P. paysoniorum), and the next season I had close to 100% emergence of both species.

Glad you stopped in at the forum!  I hope you find it as fun and informative as I do.

Rick Rodich    zone 4a.    Annual precipitation ~24 inches near Minneapolis, Minnesota, USA

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