Rent Shop Volunteer Join

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 - April 30, 2011

From: Austin, TX
Region: Southwest
Topic: Pests, Shrubs, Trees
Title: Holes in leaves of wax myrtle from Austin
Answered by: Barbara Medford

QUESTION:

I just purchased 4 of the 5 gallon Wax Myrtles at the last spring plant sale and after planting them, they are getting eaten by bugs leaving holes in the leaves. I can't find any of the bugs doing the damage. What would be good to spray on these wax myrtles for insect control? Thanks!

ANSWER:

Water. And if that doesn't work, add a little pure liquid soap to the water, and spray again.

Okay, now we've had our fun, we'll get serious. We are neither entomologists nor plant pathologists, but our experience as gardeners tells us this is probably aphid damage. Look on the underside of the wax myrtle's leaves-do you see tiny white specks moving around? Are there ants present? Is there a whitish deposit on those undersides, some of which may be developing a black moldy appearance?

Sooty mold is a fungus, or more commonly a complex of two or more fungal species, that grows on honeydew or on plant exudates. Honeydew is a waste-product of aphids and other plant-sucking insects. As honeydew is excreted by sucking insects, it falls and coats any surface upon which it lands. Sooty mold fungi invade and live upon this sugary coating. These fungi do not infest the leaf ifself. Thus, sooty mold may often be found growing on any exposed surface beneath aphid-infested trees and shrubs. Sooty mold can cause great harm to plants, however, by blocking sunlight to the leaf surface below and diminishing photosynthesis.

Sooty mold can often be successfully removed by rinsing with water from a garden hose. However, this will be most effective after the aphids or other honeydew-producing insects are destroyed. Sometimes sooty mold development is so severe and persistent that only time and exchange of leaves through the growing seasons will remove it all.

Aphids are not especially difficult to control and non-chemical methods are usually very effective. Insecticidal soaps are often the remedy of choice for many gardeners. Various brands of insecticidal soaps may be found at just about any retail nursery or garden center. Be sure to read and carefully follow all label directions when using any pesticide, organic or chemical.

 

 

More Trees Questions

Landscape Fabric for Oak Suckers in Austin
February 11, 2015 - Can landscape fabric (covered w/decorative bark mulch) be safely used to control Escarpment oak sprouts? 70-year-old knees are tired of getting down to remove. Oaks are in Circle C area of Austin
view the full question and answer

Will corn fall victim to allelopathy from hackberry in Clarkridge AR
March 30, 2013 - Will my corn be inhibited by a nearby hackberry and if so would it help to cut it down? I understand that sometimes the soil is full of the chemicals the tree produces.
view the full question and answer

Leaf spot as indicator of Oak Wilt Disease
May 26, 2007 - I live close to the Wilflower Center. I have two trees in my front yard which are just now showing brown spots on the leaves. I fear this may be oak wilt. Would it be possible for me to bring som...
view the full question and answer

Fruit on Mexican olive in Austin
June 05, 2008 - Does Mexican Olive set fruit in Austin? Does there need to be a male and female tree or not. How old does the plant have to be to set fruit? Mine is three years old but no olives. I need to know ...
view the full question and answer

Is mulch from hackberry and chinaberry trees safe for flowerbeds?
September 17, 2014 - We had to remove several large hackberry and china berry trees. Is its mulch safe to use in garden and in flower beds?
view the full question and answer

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