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
Not Yet Rated

Saturday - June 07, 2014

From: Austin, TX
Region: Southwest
Topic: Diseases and Disorders, Soils, Herbs/Forbs
Title: Stress on Goldenball leadtrees from Austin
Answered by: Barbara Medford

QUESTION:

I know of two separate instances where young Goldenball Lead Trees (leucena retusa) have shown symptoms of defoliation and a bleeding of white sap from sores that have developed on the bark. The first died aggressively. The second is under stress now. What are they susceptible to? Too much water or inadequate drainage might have weakened them for a pathogen or critter to get started?

ANSWER:

According to this USDA Plant Profile MapLeucaena retusa (Goldenball leadtree) grows in Travis and Blanco County, but the other counties where it has been reported are all in the  Big Bend area of southwest Texas, so there might be a cultural problem of which we are not aware.  If you will follow the plant link above to our webpage on this plant, you can compare the growing conditions, soils, etc. for this plant to those of the plants you have observed as being stressed.

Not having found an answer on our own website, we went hunting on the Internet, and the only clues we got were similar to our supposition that maybe it didn't really belong in Travis County, but was reported to the USDA because people were growing it here. We learned that it does not do particularly well in clay soils which we have, because it needs really good drainage. We also learned it likes sandy soils, which we don't have.

One reference mentioned it could be susceptible to root rot in poorly drained soils. From the Missouri Botanical Gardens, we found this article on Phytophthora Root Rot of Trees and Shrubs. Especiially note this paragraph:

"Life Cycle

Root rot-causing Phytophthora species can survive in the soil for years, as long as moist conditions persist. It can spread through splashing rain, irrigation water, and runoff water. Disease fungi can spread through contaminated soil and garden equipment as well. Rot is more likely to spread in early spring and late fall during cool, rainy weather. But symptoms are more likely during stress periods of low rainfall. Flooded and saturated soil conditions for 6–8 hours are especially conducive to the spread of root rots. Wounds are not required for infection."

If you are noting these symptoms in the Goldenball Leadtree, it could very well be because they are getting too much love from the gardener. If other plants nearby need more water, like non-native grasses, that may precipitate the problem. We would suggest either remediating the conditions in which the plant is being grown, or not try to grow it out of its natural region.

 

From the Image Gallery


Goldenball leadtree
Leucaena retusa

Goldenball leadtree
Leucaena retusa

Goldenball leadtree
Leucaena retusa

Goldenball leadtree
Leucaena retusa

More Soils Questions

Evergreen pet-safe shrubs for house and screening in McKinney TX
April 15, 2010 - Looking for shrub, preferably evergreen, to plant near the house that can handle wet ground and is pet (dog, cat, horse) safe. The area became boggy after we had an underground water leak that is now ...
view the full question and answer

Is cement leaching into flower beds in Colorado Springs?
May 16, 2009 - I have posed this question to a number of garden centers in our area around Colorado Springs--only to rec. a repeated--"Gee, I don't know." When we moved to our new home there was a rock concrete ...
view the full question and answer

Replacing hawthorn bush with muhly grass from Plano TX
April 10, 2014 - I am thinking of replacing a hawthorn bush with a muhly grass plant or two in an edged area with river rock cover in Plano, texas. It is the black soil and not a sandy loam. We have a sprinkler syst...
view the full question and answer

Weak stems on asters and ironweed from Woodbridge ON
June 06, 2012 - My question is in regards to plants flopping over. My smooth asters and ironweeds never seem to have strong stems. Is because the soil is too fertile or maybe too shallow?
view the full question and answer

Erosion control on slope from Columbia SC
April 25, 2013 - We are in the process of having a new home built in Columbia South Carolina. Part of the front yard has a steep slope starting approximately four feet from the corner of the house and running to the ...
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