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?

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
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
2 ratings

Wednesday - June 25, 2008

From: Italy, TX
Region: Southwest
Topic: Non-Natives, Shade Tolerant, Trees
Title: Non-blooming crape myrtle in Italy, TX
Answered by: Barbara Medford

QUESTION:

It's Italy, TX, again! Thanks for the advice and links, and I'll study those..but here's where I'm stumped on crape myrtle. I have two (almost) trees because they've been planted over 15 years ago. I have this same problem every year and here it is: one blooms like crazy and the other one doesn't. I bought them at the same time, and treat them the same. The only thing I can figure out is that the one that doesn't bloom is shaded more than the other. I cut out a few branches from two of my large trees so maybe that will work. I have had powdery mildew on both and use a fungicide to get rid of it. The second crape myrtle has bloomed a little in the past but nothing like the burst of flowers seen on its sibling a few feet away.

ANSWER:

There is a native bush or small tree, Malpighia glabra (wild crapemyrtle) that looks like a crapemyrtle but is not in the same family. It is also called a Barbados Cherry and occurs mostly in South Texas. Most of the crapemyrtles planted in gardens are native to Asia, and are selections or cultivars of Lagerstroemia indica or Lagerstroemia faurei (Japanese crapemyrtle). So, we're going to assume that is what you have in your yard. Here are the major reasons we found that prevent crapemyrtles from blooming well:

Crapemyrtles need at least 6 to 8 hours of full sun a day to flower well.

They are very drought resistant, once established, but flowering can be enhanced by irrigation during extended dry periods.

Trees that are continually fertilized with nitrogen will put on a lot of vegetative growth, but may not flower as profusely. Keep the lawn fertilizer, which is supposed to encourage green leaves, away from the crapemyrtles.

Low fertility. The crapemyrtle will benefit from application of complete fertilizer in early Spring (with a good shot of phosphorus in it) to produce enough energy for growth and flower production.

Heavily pruned crapemyrtle will put most of their energy into regrowing limbs and leaves and less energy will go into flower production. Please don't prune your plant with a chain saw; in fact, many gardeners advise not pruning at all.

Dealing with powdery mildew. Even before you pull out the fungicide, try thinning the canopy of the crapemyrtle (okay, pruning sometimes is good), to allow better air circulation. And, again, if it had more sun it probably wouldn't be quite so susceptible to powdery mildew.

You have probably diagnosed your problem correctly, that the less heavily blooming plant is in too much shade. The problem is, even when you plan ahead and put a new plant in a sunny area, the trees around it will grow, too. What was a sunny place when you planted it may be shady in a few years.

 

More Non-Natives Questions

Non-native tomato plant in Austin
August 30, 2010 - I have an upside-down tomato plant, started on July 4. For several weeks there have been 7 green tomatoes, with no further growth or ripening,despite daily watering. Am I doing something wrong?
view the full question and answer

Will roots of non-native Bottlebrush damage foundation in Weslaco TX
April 02, 2011 - I have a bottle Brush tree planted 2 feet from a brick wall. The condo board told me to remove it for fear that it may crack the foundation of the wall. I don't want to remove it. I believe they are ...
view the full question and answer

Non-native Filaree seeds for science classroom
May 30, 2008 - Can I purchase Filaree seeds for my science classroom? If so, where?
view the full question and answer

Non-native wedelia and dayflower in Lihue HI
September 03, 2009 - I have wedelia as ground covering, day flower or commelinaceae takes over. What can I use or spray to rid myself of the day flower problem?
view the full question and answer

Proper deadheading of non-natives Arabian Jasmine and Crape myrtle from Las Vegas
July 23, 2010 - Advise please on proper deadheading of Arabian Jasmine, and of Crape Myrtle. They are both blooming great but I want to know once the petals fall should I deadhead and will it help them to bloom agai...
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.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP
© 2014 Lady Bird Johnson Wildflower Center