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?

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
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
1 rating

Friday - August 09, 2013

From: San Antonio, TX
Region: Southwest
Topic: Container Gardens, Planting, Herbs/Forbs
Title: Growing conditions for Giant Coneflower from San Antonio
Answered by: Barbara Medford

QUESTION:

Rudbeckia maxima is considered to be a perennial plant for the sun but I have had a difficult time maintaining it in a pot in full sun before attempting to plant. Do you feel that it will survive and thrive in the sun in the San Antonio area with temperatures reaching 105? Will it need deep soil and lots of water?

ANSWER:

Here are the growing conditions for Rudbeckia maxima (Giant coneflower) from our webpage on that plant:

"Growing Conditions

Water Use: High
Light Requirement: Sun , Part Shade
Soil Moisture: Moist
CaCO3 Tolerance: Low
Drought Tolerance: Low"

And

"Native Habitat: Found in moist open places. Forming beds in low ground, sandy or silty soils; east Texas west to East Cross Timbers. Seems pretty drought resistance despite its swampy origins."

From this, we are inferring a need for part shade (2 to 6 hours of sun a day) in such a hot summer, as well as lots of water. The problem for plants in pots in either extreme heat or cold is that a few inches of potting soil and the sides of a pot are not much insulation for the roots. Its native habitat appears to be low places and swampy soil, indicating some shade during the day. Also, the insulation of the earth around any roots is more valuable than any kind of pot material for the preservation of the roots. We would suggest you either move the pots to a shadier spot, or transplant the coneflowers into soil earlier in the season, before the heat becomes so intense.

 

From the Image Gallery


Giant coneflower
Rudbeckia maxima

Giant coneflower
Rudbeckia maxima

Giant coneflower
Rudbeckia maxima

More Container Gardens Questions

Failure to thrive of closet plant
August 13, 2008 - I have a closet plant that is old and was doing fine and then started having droopy leaves. It needed to be in a larger pot so I transplanted into a larger pot with new potting soil. It continues to...
view the full question and answer

Container plants for pool area in Killeen TX
March 08, 2009 - We live in Central Texas (Killeen). We want to put some container plants around our pool. (backyard with pool is all cement). We want some larger stuff, like maybe bamboo, elephant ears, etc. What pla...
view the full question and answer

Winter plants for windowbox in Piedmont SC
October 26, 2012 - What kind of outdoor window box spruss can grow in upstate South Carolina in the winter months?
view the full question and answer

Possibility of invasiveness of blackberry bush
March 27, 2008 - I bought a blackberry bush from Home Depot last year. My sister said if I planted it in the ground it would take over my lawn. So I put it in a big planter up against my fence, but I'd like to put it...
view the full question and answer

Container native plants for New York area
June 10, 2009 - I live near Lake Ontario (zip 14098). Would like to know what to plant in window boxes that have southern exposure and are in direct sun 4-6 hrs a day
view the full question and answer

Smarty Plants's Facebook profile Support the Wildflower Center by Donating Online or Becoming a Member today.

Mr. Smarty Plants wants you to be his Facebook friend. Click the Facebook icon to add yourself to Mr. Smarty Plants list of friends.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP
© 2014 Lady Bird Johnson Wildflower Center