En Español

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

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

Sunday - October 07, 2007

From: Austin, TX
Region: Southwest
Topic: Soils, Shrubs
Title: Potting soil recipe for azaleas
Answered by: Barbara Medford


I have a couple of Azaleas in pots that need repotting.I can't remember the recipe for the medium I put them in last time other than pine bark mulch. I think there were three ingredients. What is your recommendation?


Even Mr. Smarty Plants can learn something new. We thought something as exotic-looking as an azalea must surely be a sub-tropical non-native. But, a search in our Native Plant Database turned up 26 native varieties. Not that it has to be native to be grown in a pot, of course, but at the Lady Bird Johnson Wildflower Center we try to concentrate on the care and propagation of plants native to North America. Turns out that azaleas include not only natives to North America, but we found 3 native to Texas! Among the other things we learned is that all azaleas are rhododendrons but not all rhododendrons are azaleas. We learned that wild azaleas are found on every continent except Africa and South America, with Southwestern China and Papua New Guinea having the most species. They have been hybridized for hundreds of years, and in the U.S. the natives do best in the Pacific northwest where rainfall is plentiful and winter temperatures are not too low. For more information, go to this site on Care of Azaleas.

But that's not what you asked, was it? You wanted a recipe for potting soil for containerized azaleas. On the above-mentioned website, we finally found a recommended recipe. We don't know if this was the one you were thinking of, but we hope so. It calls for equal proportions of peat moss, vermiculite, potting soil and coarse sand.

And, since we found those Texas native azaleas, let us tell you about them. They are Rhododendron canescens (mountain azalea), Rhododendron oblongifolium (Texas azalea), and Rhododendron prinophyllum (early azalea), pictures below.


Rhododendron canescens

Rhododendron oblongifolium

Rhododendron prinophyllum





More Soils Questions

Shriveling agave from Miami Florida
August 23, 2013 - Dear Mr. Smarty Plants, Most upset - My beautiful agave (wish I could have submitted an image) has stared to misbehave. The once first liquid filled leaves, are starting to look more like the skin ...
view the full question and answer

Need Plants and Soil for a Green Roof in Buffalo, TX
September 13, 2010 - I'm building a green roof on my cabin in the Buffalo, Texas, area. Would you know what soil and plants would be best suited for that area? I have a lot of sand I could use, but didn't know if that...
view the full question and answer

Soils for spiderwort from Round Rock TX
August 08, 2013 - We have spiderworts growing naturally in our backyard. We put a large circle around them them with limestone rock (as our beds have) to make their own bed as they clumped in one area. What kind of s...
view the full question and answer

Is California fan palm found on Edwards Plateau from Austin
January 18, 2013 - Is the following Palm, Washingtonia filifera, found in the Texas Hill Country, specifically the Edwards Plateau or Balcones Canyonlands NWR.
view the full question and answer

Yellowing leaves of Texas Sage (Cenizo) from Las Vegas NV
November 21, 2013 - Leaves of Texas Sage are turning yellow. Can you tell me why?
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
© 2016 Lady Bird Johnson Wildflower Center