En EspaŅol

Q. Who is Mr. Smarty Plants?

A: There are those who suspect Wildflower Center volunteers are the culpable and capable culprits. Yet, others think staff members play some, albeit small, role. You can torture us with your plant questions, but we will never reveal the Green Guru's secret identity.

Help us grow by giving to the Plant Database Fund or by becoming a member

Did you know you can access the Native Plant Information Network with your web-enabled smartphone?


Ask Mr. Smarty Plants

Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

Search Smarty Plants
See a list of all Smarty Plants questions
Can't find the answer in our existing FAQs, submit a question to Mr. Smarty Plants.
Need help with plant identification, visit the plant identification page.
rate this answer
3 ratings

Friday - June 03, 2011

From: Denton, TX
Region: Southwest
Topic: Propagation
Title: germinating Gulf coast penstemon and purple coneflower
Answered by: Guy Thompson


I'm interested in propagating gulf coast penstemon (penstemon tenuis) from seed. Do I have to mascerate the 'berries' to remove the pulp from the seed, and do I have to stratify the seed to get the seed to germinate? In other words is a cold treatment such as stratification or overwintering necessary for germination. I'm also wondering what light regime works best-do they need light or darkness to germinate? If they need light would simple direct sowing by hand broadcasting work; and if they need darkness how deep should I sow the seed. Finally, can I get the seed to germinate this year before the winter sets in so I'll have a jump on next season? I also have another question about purple prairie cone flower (echinacea purpurea). In 'Native Texas Plants' the Wasowskis state that the centers hold their color and shape for a long time after the petals drop as the seed ripen. How long is necessary for the seed to ripen, how do you tell when the seeds are ripe, and is this process seen in other plants? I look forward to your responses.


You should be able to get good results with your efforts to germinate Penstemon tenuis (Brazos penstemon) , commonly known as Gulf Coast Penstemon.  This penstemon is known to reseed freely.  However, like most penstemon species, it benefits from a cold treatment.  (Sow under thin cover 3 wks @ 40ºF (4ºC) ) is the recommendation of an authoritative web site by Jim Swayne.  I suggest that you wait until the seed pods dry and just begin to open (it shouldn't take long), then stratify if you hope to get germination the same season.  No light is required.

With respect to Echinacea purpurea (Eastern purple coneflower), I think you should wait until the centers begin to turn dark and feel dry to the touch.  Depending on the weather this should take a few weeks after the blooms fully open. The seeds should have reached maximum size by that time. Recipes for harvesting the seeds and germinating them are described in the attached article.


From the Image Gallery

Brazos penstemon
Penstemon tenuis

Eastern purple coneflower
Echinacea purpurea

More Propagation Questions

Protecting agave pups in San Antonio
April 23, 2013 - I would like to share the soon to happen bloom of two century plants on my property; they are sisters planted at the same time. I am sad to know they will die but will do all that I can to protect the...
view the full question and answer

Propagation of American Bittersweet
December 29, 2004 - Will American Bittersweet grow in Central Texas?
view the full question and answer

Purchase of Galphimia angustifolia from Austin
June 08, 2014 - I have a Thryallis, Galphimia augustifolia, or Thryallis autustifolia, growing from a limestone ledge in my yard in west Austin TX. I have tried unsuccessfully to buy this native. Do you sell it at t...
view the full question and answer

Winter care of Asclepias tuberosa from Austin
October 31, 2013 - We have several asclepias tuberosa (Butterflyweed). Monarch caterpillars have found and denuded them. We are excited about all of the Monarch caterpillars, but unsure of what to do next. What do we...
view the full question and answer

Transplanting of yucca plants
May 26, 2006 - We have several Arkansas Yucca plants in our yard that we want to transplant to a plant bed. How do we do that?
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
© 2015 Lady Bird Johnson Wildflower Center