Host an Event Volunteer Join Tickets

Support the plant database you love!

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

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 Herbs/Forbs Questions

Using a brush hog on acreage on Bear Creek in Austin, TX.
July 25, 2012 - We have 8 acres off 1826 situated on Bear Creek. It has open areas with scattered large trees (cedar elm, live oak, white oak). Cedars or junipers only along the the lot lines. We've been told we...
view the full question and answer

Problems with gaura in Kyle TX
May 10, 2011 - Gaura - I seem to have something going on with this plant. I've tried fungicide that also works on mealy bugs and spider mites, etc., but they're looking rather puny? Any suggestions? thanks
view the full question and answer

Native Wildflowers and Grasses for Texas Acreage
April 15, 2015 - I recently purchased about 36 acres in Somervell County, Texas where cedar had been bulldozed and burned (many large spots). What would be the best native flowers or grasses to replant in that area? L...
view the full question and answer

Plant identification from Springfield MA
July 19, 2009 - We have a house next to us that is vacant. The lawn has not been mowed in months. a tall flower has grown amongst the grass and weeds. It is about 3 to 4 feet tall green stem and the flower is about 2...
view the full question and answer

Trimming native salvias in January
January 17, 2008 - I have heard you can trim Hot Lips, Raspberry and other salvias back severely in January, to about six inches from the ground. Is this correct?
view the full question and answer

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