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 of potted verbena to bloom
July 20, 2008 - I have a trailing purple verbena that won't bloom. It is in a container, not in the ground, and gets lots of sun. What is the problem?
view the full question and answer

Planter boxes on a roof deck in Boston MA
May 20, 2013 - What will grow in planter boxes on a roof deck in Boston ma? We are planning to make our own planters to sit on the framing "outside" our deck rail. We have 4 ft from the rail to the edge of the ho...
view the full question and answer

Keeping bonsai plants alive in Athol MA
September 21, 2009 - For the past 12 years I have raised bonsai plants in AL and FL, but recently moved back to central MA. My collections consists of Japanese maples, ginkos, bald cypress and ficus benjamina. I have a ...
view the full question and answer

Plants for indoor container gardening from Lax Vegas NV
May 10, 2013 - What is an good flower to grow in a pot? I live in a apt., and like roses,tulips etc. if that helps any.
view the full question and answer

Gregg's mistflower in pot from Vail AZ
August 04, 2012 - I recently bought a Gregg's Mist plant and don't know much about it. I live in Arizona and was wondering how well the plant will do if I plant it in a large ceramic pot? Will it continue to grow? ...
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