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

Monday - July 20, 2009

From: Whitney, TX
Region: Southwest
Topic: Non-Natives, Compost and Mulch, Diseases and Disorders, Watering, Shrubs
Title: Yellow bands around edges of leaves in Whitney TX
Answered by: Barbara Medford


How can you tell whether esperanzas are getting too much water or not enough - ours have a small yellow band around the edges of the leaves - crape myrtles - same question


Tecoma stans (yellow trumpetbush) (Esperanza) is native to North America and to Texas, but most of the areas where it is growing are in far south and southwest Texas. It thrives in rocky, alkaline soils and needs watering only about every one or two weeks. We are not sure what kind of soil you have in your area of the state, but if  you have a clay soil, and have not amended the soil for better drainage, that could be the problem. While Texas has been uncommonly dry this year, you have probably been watering your garden, and water may simply be standing on the roots of the bush. If your Yellow Bells has been planted recently, continuing to water is probably important, but drainage is even more important. Work some compost into the soil around the roots and avoid watering with an automatic sprinkler system. Overhead watering (except rain) can cause problems for some desert plants. It also does not need fertilizer, since it is native.

We frequently find that chlorosis can cause yellowing leaves. In the case of the Esperanza, the overwatering of the roots may be preventing the roots from accessing some of the vital trace elements in the soil, especially iron, and this can cause chlorosis. In the case of Lagerstroemia indica, Crape myrtle) there may be the same problem, but in this case we have no information on it in our Native Plant Database because it is non-native. At the Lady Bird Johnson Wildflower Center we are committed to the growth, care and propagation of plants native not only to North america, but to the spot in which they are being grown. 

We checked on the possibility of leaf spot diseases, and found none that fit the description you gave. This Floridata site can give you more information on Lagerstroemia indica but, again, good drainage is about the only recommendation.  Both plants would likely benefit from composting and mulching, and both should be in full sun, 6 or more hours of sun a day.

Tecoma stans

Tecoma stans

Tecoma stans

Tecoma stans




More Shrubs Questions

How to plant a gooseberry bush
November 22, 2008 - Please, if somebody can help, I need to know how to plant the gooseberry bush. Thanks,
view the full question and answer

Information about blackleaf elderberry
July 03, 2008 - I was given a blackleaf elderberry. Do I plant this tree in shade or sun? Also, does it require a lot of moisture? Thank you.
view the full question and answer

Evergreen for privacy in PA
July 18, 2011 - We need to plant a privacy/sound barrier hedge/hedgerow and my husband says it must be evergreen. I am not familiar with which species would be native to our area and I just don't trust those big sto...
view the full question and answer

Plant ID and pruning in Portage IN
April 09, 2009 - I'm looking for information on trimming a bush about 6 feet in diameter with orange horns in bloom and its name.
view the full question and answer

Need Small Native Shrub in Dallas, TX
September 17, 2010 - We live in Dallas and are looking for a dwarf bush that we can plant in the space between the sidewalk and the street in front of our house. It would receive full sun to partial shade. We would like...
view the full question and answer

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