Native Plants

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

1 rating

Wednesday - August 20, 2008

From: Austin, TX
Region: Southwest
Topic: Non-Natives
Title: Viability of non-native Royal Poinciana in Austin
Answered by: Barbara Medford

QUESTION:

My question is about the tree called Royal Poinciana that grows so well in the Rio Grande Valley. I realise it isn't a native but hope you have an opinion about its chances of survival in Austin. I believe it is actually a Caesalpinia.

ANSWER:

The Delonix regia, Family Caesalpineaceae, is endemic to Madagascar, where it is endangered, but widely cultivated elsewhere. It is a tropical legume, related to the mimosa. One website we saw said it was hardy from Zone 10a to 11; another said 10b to 11, a pretty tight range of hardiness, and not representative of Austin! About the best you can hope for around here is Zones 7a to 8b. Information we found indicated that it would not grow well in a large pot in a greenhouse situation, and refused to bloom in a pot. If you are game to give it a try, it needs to be well-watered until established, then only during severe drought. You should not plant the tree closer than about 10 feet from a pavement or sidewalks, since large surface roots often grow beneath them and destroy them. This USDA Forest Service website on Royal Poinciana will give you more information.