Host an Event Volunteer Join Tickets

Support the plant database you love!

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?

Share

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

Please forgive us, but Mr. Smarty Plants has been overwhelmed by a flood of mail and must take a break for awhile to catch up. We hope to be accepting new questions again soon. Thank you!

Need help with plant identification, visit the plant identification page.

 
rate this answer
Not Yet Rated

Thursday - August 08, 2013

From: Birdeye, AR
Region: Southeast
Topic: Propagation, Seeds and Seeding, Herbs/Forbs
Title: Cold stratification of Rudbeckcia maxima from Birdeye AR
Answered by: Barbara Medford

QUESTION:

How long do I cold stratify Rudbeckia maxima seeds that I wild harvested? Can I put them in the freezer instead of fridge? Do I need to make sure they are completely dry before cold strat?

ANSWER:

There are 20 members of the Rudbeckia genus native to North America, of which 11 are native to Arkansas. However, this USDA Plant Profile Map shows that Rudbeckia maxima (Giant coneflower) is only native to 3 counties on the western edge of Arkansas, clear across the state from Cross County, so you may have harvested seeds from a very similar species or even from a hybrid. However, it really doesn't matter too much, they are closely related enough that if we can find propagation instructions they should be applicable to any of the Rudbeckia species.

Our webpage on R. maxima did not have propagation instructions on it, but the page on R. hirta, also native to Arkansas, had these instructions:

"Propagation

Propagation Material: Seeds
Description: Propagates very easily from seed sown in fall or spring. Spring-sown seed should be stratified. Rake seed into a loose topsoil or cover with ¼ to ½ inch of soil or mulch. If possible, supplement with water if fall or spring rains are infrequent and light. The seed requires several days of moisture and should germinate in one to two weeks.
Seed Collection: The nutlets turn charcoal-gray at maturity, usually 3-4 weeks after the bloom period. Seeds are mature at this time, but they are easier to collect after cones lose their tight compact stucture. Store dry in sealed, refrigerated containers.
Seed Treatment: Stratify for 3 months at 40 degrees.
Commercially Avail: yes
Maintenance: Black-eyed Susans are drought tolerant but respond well to an occasional watering. Additional irrigation in a dry year will improve the density of the stand and lengthen the flowering season. Do not mow until after the plants have formed mature seed cones, about three to four weeks after flowering. (Check by breaking a cone open and if the seeds are dark, they are mature.) The number of volunteer plants can be limited by removing the seed heads after the flowers are done."

Since this member of the Mr. Smarty Plants Team has no personal experience with cold stratification of seeds, we found these instructions from Wildones.org. Hopefully, you will find the method that works best for you.

 

From the Image Gallery


Giant coneflower
Rudbeckia maxima

Giant coneflower
Rudbeckia maxima

Giant coneflower
Rudbeckia maxima

More Propagation Questions

Difference between white and red berried versions of Callicarpa americana
March 24, 2007 - I have seen many American Beautyberry Bushes [Callicarpa americana] but it was not until I moved into the Big Thicket region that I had ever seen a white berried one. There is no difference botanicall...
view the full question and answer

Yucca sprouting shoots in Oxfordshire, England
July 11, 2010 - I have a 20ft outdoor yucca with four huge branches.It is 11 years old. For the first time it has sprouted two side shoots on one of the trunks. They are about 12 inches in length. What is the best wa...
view the full question and answer

Proliferation of Small Palafoxia in Dallas Co. TX
June 07, 2013 - A few years ago I noticed a new wildflower I hadn't seen before in the southwest Dallas County area. I found the name to be Small Palafoxia. It was growing along the edges of HWy 67 in Duncanville ...
view the full question and answer

Propagating Dakota vervain (Glandularia binpinnatifida)
August 07, 2008 - Dakota Vervain. We recently moved into a new house in Henly--Hays/Blanco county line. Mother nature was kind enough to provide us w/Dakota Vervain in some of our planting beds while we are getting...
view the full question and answer

Plants for elementary school grow lab in New York
March 14, 2007 - What can we grow in a grow lab in our elementary school library from seed now that will bloom by June or what interesting looking established plants can we put in this grow lab that will have meaning ...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.