En EspaŅol

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
Can't find the answer in our existing FAQs, submit a question to Mr. Smarty Plants.
Need help with plant identification, visit the plant identification page.
rate this answer
1 rating

Thursday - October 18, 2007

From: San Angelo, TX
Region: Southwest
Topic: Diseases and Disorders, Shrubs
Title: Nutrient imbalance in Tecoma stans
Answered by: Jimmy Mills


I have two Tecoma stans on the north-east side of my yard. They have grown very tall (5') but have not bloomed all summer. Last summer they bloomed profusely. Any idea what the problem might be?


Tecoma stans (yellow trumpetbush) aka Esperanza or Yellow Bells is a popular landscape plant that is native to Texas and Northern Mexico, and the cultivar "Gold Star", developed by a plant breeder in San Antonio, TX, has become a favorite in Texas due to its abundant flower production and its shorter height.

Since you had profuse blooms last summer, but none this summer, the question to ask yourself is what am I doing differently this summer? Flowering is a complex process that is influenced by several factors including amount of sunlight, amount of water, and nutrient balance, particularly the nitrogen to phosphorous (N/P) ratio. Unless you have transplanted the Tecoma or have had an unusual amount of rainfall, you can probably eliminate the first two. Austin has had a really wet summer, and the Tecoma here are blooming spectacularly.
That leaves nutrient levels. If you fertilized in the spring with a fertilizer that had higher nitrogen content relative to phosphorous, this may be your problem. I'm including links to Texas A&M and Penn State that do a great job of explaining the N/P ratio and its effect on flowering.

You might also check to make sure that there aren't any insects that are attacking the immature buds. 


From the Image Gallery

Yellow bells
Tecoma stans

More Diseases and Disorders Questions

Use of surfactants with herbicide for water
January 05, 2008 - I read the article on frogs and the use of Rodeo. Your answer was correct, but to the best of my knowledge, Rodeo is approved for use near water only because it lacks a surfactant. When surfactant...
view the full question and answer

Non-native sedum 'Burrito' sunburned in Providence RI?
June 28, 2010 - I have a sedum burrito that I keep outside and receives bright sun for around 6 hours a day. it looks like it's getting sunburned, the leaves are getting shriveled and browning on the tips. I've bro...
view the full question and answer

Pruning mature cedar elm trees in San Antonio
September 14, 2008 - When is the right time to prune my several mature cedar elm trees? I'm in San Antonio, and they have never been trimmed in the 55 years we have lived in this home. I have several that are at least 7...
view the full question and answer

Which plants are resistant to dog urine in Ashmore, IL??
May 21, 2012 - Which native plants are resistant to dogs urinating on them?
view the full question and answer

Non-native Chamaecyparis pisiflora turning brown in Fuqua-Varina NC
December 10, 2012 - I have a "Soft Serve False Cypress" Chamaecyparis pisifera'Dow Whiting PPAF, that has only been in the ground for 6-7 months. I just noticed that the branches and leaves are starting to die, turni...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
© 2015 Lady Bird Johnson Wildflower Center