Host an Event Volunteer Join Tickets

Your gift keeps resources like this database thriving!

DONATE TODAY

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

Friday - June 15, 2007

From: Round Rock, TX
Region: Southwest
Topic: Non-Natives
Title: Decline in non-native crape myrtles
Answered by: Joe Marcus

QUESTION:

I live in Round Rock and the ground is rocky about one foot beneath the surface. I have about 14 crape myrtles that have been doing very well for about 6 years now. Last year the leaves on 1 started turning red and then yellow and it didn't grow or flower no matter what I did. This year, 2 more besides the 1 have also started turning yellow. I sprayed for mold and also used fertilizer with iron but nothing helps. What could be going on with them?

ANSWER:

The focus of study and the limit of expertise of the Lady Bird Johnson Wildflower Center is limited to plants native to North America. Crape myrtles (Lagerstroemia spp.) are native to other parts of the world. However, we can give you some general advice. Crape myrtles are normally not very susceptible to disease or insect problems. High nitrogen fertilization can cause problems similar to those you describe. At any rate, it is usually not a good idea to feed declining plants. We would suspect a problem associated with nutrition or a root-related problem.
 

More Non-Natives Questions

Questions about lilies from Trussville AL
January 10, 2012 - How can I tell what kind of lily I have? Or better yet,what is the difference between Asiatic lily and a daylily? I also noticed someone asked about Cahaba lily. Just want to let you know I grow Caha...
view the full question and answer

Indoor non-native palm tree turning yellow from Leavenworth WA
March 22, 2011 - Why are my indoor palm plant leaves turning yellow. It's about 4 feet bought at local Home Depot store, and it was beautiful when I brought it home. It gets plenty of light. I have only had it for ...
view the full question and answer

Need help with Wheeler's Dwarf Pittosporum
September 02, 2015 - We have about five Dwarf Wheeler Pittosporum plants. All of them are mature and were doing well. I was on vacation for a week or so and when I came back I saw of each of them is plant 90% dead. The d...
view the full question and answer

Controlling Rapistrum rugosum (annual bastardcabbage)
March 09, 2012 - The invasive, Rapistrum rugosum, seems to be especially ubiquitous this year. I communicated with Dr. Mark Simmons a few years ago regarding his research, which indicated that over-sowing wit...
view the full question and answer

Winter care for non-native ice plant in Virginia
August 15, 2008 - I have an ice plant in my garden and it is doing very well. What would be the care for winter. Ground seldom freezes, temperatures mostly 20 but can get in single digit occasionally. Very little snow ...
view the full question and answer

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