En Español

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

Sunday - August 08, 2010

From: Austin, TX
Region: Southwest
Topic: Planting, Transplants, Shrubs
Title: Sumacs under live oaks dying in Austin
Answered by: Barbara Medford

QUESTION:

Converted my yard to native plants last fall. All of the fragrant and evergreen sumacs are dying off one by one - they have never thrived. I ensure they get a good soaking at least once a week. I was warned not to fertilize them or it will make them deer fodder. They are placed as understory for our live oaks and mulched with a couple inches of oak leaf/hardwood mulch. What can I do to save the few that are left?

ANSWER:

Can we assume that the sumacs were planted when you did your conversion to native plants? If so, they have not been in the ground very long, and could still be suffering from transplant shock. We always check growing conditions on the page in our database for plants that are not doing well, and ask ourselves "Is this a plant in the wrong place, or the wrong plant for the place or was it planted at the wrong time?"  According to this USDA Plant Profile for Rhus aromatica (fragrant sumac) it is not native to Travis County, but does grow in some counties to the north and east. However, according to this USDA Plant Profile, Rhus virens (evergreen sumac) is native to Travis County and several counties in the vicinity. Both require sun (6 or more hours of sun a day) or part shade (2 to 6 hours of sun), and tend to develop into thickets in open fields in the wild. Since they both are native to this area, we can assume they are in the right place in terms of soil, climate and rainfall. 

So, what's left? You say they were planted as understory trees to live oaks. There is a lot being said now about the allelopathy of oaks; that is, emitting substances that discourage competition from other plants. These substances can be present in fallen leaves, roots, and bark. If the oak trees were already well-established, it just may be that there is not room in your space for both, and the oak trees are winning.  Perhaps even the amount of water they are getting is inappropriate, as the growing conditions for both include low water use, dry soil, and tolerance of drouth.

If you have seen no insects or signs of disease on the sumacs, and they are supposed to be very resistant to both, we can only assume that the environment is wrong, including being planted beneath oak trees and mulched with oak leaves.  How to help the remaining ones survive? You could try limbing up the live oaks to create more sunlight, cutting down on the watering, and raking away the oak leaf mulch. Will those work? Sorry, we simply don't know. 

We want to caution you about limbing up or pruning your live oaks. From the Texas Oak Wilt Information Partnership comes these precautions about pruning live oaks, which are being devastated in Central Texas by Oak Wilt.

"All wounding of oaks (including pruning) should be avoided from February through June. The least hazardous periods for pruning are during the coldest days in midwinter and extended hot periods in mid- to late summer. Regardless of season, all pruning cuts or other wounds to oak trees, including freshly-cut stumps and damaged surface roots, should be treated immediately with a wound or latex paint to prevent exposure to contaminated insect vectors."

From our Native Plant Image Gallery:


Rhus aromatica

Rhus aromatica

Rhus virens

Rhus virens

 

 

 

More Shrubs Questions

Twenty year old Texas Mountain Laurel isn't blooming.
March 09, 2015 - I have 20-year-old Texas Mountain Laurel in a fairly poor, clay-type soil. It hasn't bloomed very well the last couple years. Can you recommend a fertilizer to improve the blooms?
view the full question and answer

Evergreen fast-growing native shrubs for privacy shield in Baytown, TX
March 07, 2006 - A gas well is going in across the road. We need a fast growing native tall shrub to line our property next to the road. It needs to maintain its leaves in the winter also. We hope to cut down on th...
view the full question and answer

Yellow bands around edges of leaves in Whitney TX
July 20, 2009 - How can you tell whether esperanzas are getting too much water or not enough - ours have a small yellow band around the edges of the leaves - crape myrtles - same question
view the full question and answer

How will my Texas Mountain Laurel survive clay soil?
June 09, 2009 - Mr. Smarty Pants: I live in a new neighborhood (brownfield site) in Central Austin where the developers have put fill in the yards. After not much more than 2 inches of topsoil you encounter fairl...
view the full question and answer

Transplant shock in Vacccinum corymbosum (highbush blueberry)
June 28, 2007 - Blueberry plants - We planted Northland and Blue Crop, 2 of each. All 4 plants have some leaves that are turning brown. This starts at the tip of the leaf, eventually encompasses the entire leaf, a...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | JOBS | SITEMAP | STAFF INTRANET
© 2016 Lady Bird Johnson Wildflower Center