Contact Us Host an Event Volunteer Join

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

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

QUESTION:

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

ANSWER:

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 Watering Questions

Hollies not retaining leaves in Tulsa
August 10, 2008 - I have Little Red Hollies that have lost their leaves, some areas being bald. They are also not full - you can see through them. These were planted in this condition Spring of '08 and have been wat...
view the full question and answer

Yucca rostrata needs some help in Austin, TX.
September 16, 2013 - We planted an expensive 5-6 foot Yucca rostrata last fall. It bloomed beautifully in the spring. We installed an irrigation link to water the recently planted areas with succulents, viburnums, spart...
view the full question and answer

Patio plants suffering from heat in Austin
August 22, 2010 - My patio plants are burning up from the intense sun of Austin's August. Last year it even burned the leaves. Besides moving 40 plants to a shadier spot do you have suggestions on how to protect the...
view the full question and answer

Topmost leaves on yucca are brown
June 08, 2009 - I live in the Lansing, Michigan area, in the lower peninsula and have a couple yuccas whose topmost leaves are brown emerging from winter. Do I prune those, or has the plant died? Thank you.
view the full question and answer

Correct cultural conditions for liatris
April 15, 2008 - I recently bought some gayfeather (liatris pycnostachya) and planted in my yard in a nice full sun spot. Gets sun for roughly 10 hours a day. However, it's also the single driest spot in my yard (jus...
view the full question and answer

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