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
4 ratings

Friday - August 24, 2012

From: Phoenix, AZ
Region: Southeast
Topic: Compost and Mulch, Watering, Shrubs
Title: Ailing Tecoma stans from Phoenix AZ
Answered by: Barbara Medford


I have several young Tecoma plants in my Phoenix, AZ garden. I planted them in June and have tended to them over the summer. They are watered twice daily. On some of the plants, I've noticed two oddities with the leaves. While most of the leaves are fine, the leaves towards the top and side of the bush appear to be devoid of the green leaf material so that it looks like a skeleton of the leaf - not all the leaf, just part of the leaf. The other problem has several leaves that have a cocoon like appearance although there doesn't appear to be an occupant. There are tiny black specks (excrement?)on some of the leaves. I have removed the unhealthy looking leaves and even cut the entire leaf section off. Within a couple days, the same problems can be found. I cannot see anything eating the leaves day or at night. Do you have any idea what is going on with my Tecomas? Thanks!


We realize you are having too much heat and intermittent sandstorms in Phoenix, but Tecoma stans (Yellow bells) is a desert plant, native to Arizona. It would have been better to have planted them in the cooler part of the year, like from November to January. Woody plants are very susceptible to transplant shock

Previously answered question on Tecoma stans (Yellow bells)Too much water, from Florida.

Please read this article from the University of Illinois on Chlorosis, which often is the result of nitrogen deficiency in the plant.

So, we have established three possible reasons for the failure of your yellow bells to thrive and all are linked to the time and method of planting. If your plant was not planted to allow for good drainage, such as adding compost or other organic material to the soil, the roots are drowning. The loss of green in the leaves is lack of chlorophyll, again a result of too much water on those roots.

From another previous answer:

"Chlorosis is a yellowing of leaf tissue due to a lack of chlorophyll. Possible causes of chlorosis include poor drainage, damaged roots, compacted roots, high alkalinity, and nutrient deficiencies in the plant. Nutrient deficiencies may occur because there is an insufficient amount in the soil or because the nutrients are unavailable due to a high pH (alkaline soil). Or the nutrients may not be absorbed due to injured roots or poor root growth."

Our recommendations:

1. Since you can't undo planting a woody plant in June, let a lesson be learned: Don't do it again.

2.  If you didn't plant with organic material, put a good quality shredded bark mulch over the roots. This will shelter the roots from heat and, as it decomposes, it will sink down into the soil and help amend it.

3.  Since your soil is almost certainly alkaline, take the planting provisos above to heart for all planting. Drainage, especially for desert plants, is vital for accessibility of moisture and nutrients. Compost, compost, compost.

4. Cut out all that water, probably a thorough watering once a week is sufficient. And no fertilizer. Most native plants do not need fertilizer and this plant particularly dislikes it.


From the Image Gallery

Yellow bells
Tecoma stans

Yellow bells
Tecoma stans

Yellow bells
Tecoma stans

More Watering Questions

Watering oaks in Houston, TX.
June 07, 2011 - Our yard (Real County, TX.) has many oak trees. We never water these trees, but I wonder if you recommend watering during this extreme drought. The trees look very stressed and are covered in ball m...
view the full question and answer

Care in planting native Shumard oaks
April 16, 2008 - I am going to plant 3 shumard red oaks on the west side of my property. The land is basically rocky. What should I put in the holes to help the tree grow?
view the full question and answer

Greywater effect on plants from Dallas
June 09, 2013 - How does gray water affect plants?
view the full question and answer

Care of Live Oaks
July 11, 2012 - We have Two Young Live Oaks in the front of Our home. We had them treated for insects, ect. Now what can we do to make them Full Green and Happy Happy Happy again.Thank You
view the full question and answer

Is installing irrigation with Habiturf a good idea in Round Rock Texas?
December 05, 2011 - Mr. Smarty Plants, I am in the process of planning a new lawn in my front yard. We have decided to plant the Habiturf seed mix (thank you, by the way). Originally, we planned on installing a spri...
view the full question and answer

Smarty Plants's Facebook profile Support the Wildflower Center by Donating Online or Becoming a Member today.

Mr. Smarty Plants wants you to be his Facebook friend. Click the Facebook icon to add yourself to Mr. Smarty Plants list of friends.
© 2015 Lady Bird Johnson Wildflower Center