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?


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

Tuesday - August 28, 2007

From: Austin, TX
Region: Southwest
Topic: Non-Natives, Diseases and Disorders, Trees
Title: Oak leaf fall causing ivy damage
Answered by: Barbara Medford


I read the A/Q in the Austin American-Statesman Saturday, August 25, regarding the leaves falling now from the live oaks. I am experiencing the same thing, but it is the leaves of my post oaks that are falling much too soon. The damage is that my English ivy is dying. Please advise.


Okay, we now come to the point about use of native plants in your landscape. Quercus stellata (post oak) is a native Texas oak, very drought resistant, with large leaves providing shade in the summer garden. They are seldom seen in nurseries, because they are very difficult to transplant; therefore, unless you had the post oak on land where your house is built, you probably wouldn't have it at all. Quercus stellata takes care of its own propagation. Many gardeners, as you have done, use mature native oaks to give shade and shelter to shade-loving ground covers.

Hedera helix, English ivy, is a native of most of Europe and southwest Asia. This summer, in Central Texas, for two months we had a climate like the regions where English ivy originated, cool, cloudy, and rainy. The post oak, unused to such conditions, dropped some leaves in protest. Then, summer came back to Central Texas, along with normal heat and bright sunshine, and the English ivy had lost some of its protection. It is suffering from something like sunburn, as the large, dark leaves are suddenly getting much more sun than they customarily do. Under normal circumstances, by the time the post oak dropped its leaves in the fall, the weather would be cooler, the sun lower, rain more frequent and the English ivy would be fine. The native post oak will easily survive this sudden change, because it IS a native, and its species has seen this kind of trick played by Texas weather before. We suspect the English ivy will also survive; even though it is not a native. English ivy, in fact, can be pretty aggressive in shady landscapes, and in the Pacific Northwest where the climate is similar to that in the native home of Hedera helix, it is often considered invasive. A little more water and perhaps trimming back long runners of the ivy that have browned or lost leaves should tide it over.

Quercus stellata




More Non-Natives Questions

Will frozen non-native agapanthus come back from freeze in Austin?
February 06, 2011 - I don't know if its a native plant, but my agapanthus got frozen in our recent cold weather. Will they come back; should I trim off the tops?
view the full question and answer

Invasive non-native mulberry and groundcover in Jacksonville FL
October 02, 2011 - Northeast Florida (Jacksonville) inland. My mulberry tree provides dense shade in the summer and filtered light the other seasons, leaving sand in its growing area. What fast growing ground cover woul...
view the full question and answer

Pruning non-native Japanese maple
June 03, 2008 - Can you tell me how to properly prune a Japanese maple?
view the full question and answer

Non-native, invasive mimosa trees in Vincennes IN
April 29, 2014 - I have 3 Mimosa trees here in Vincennes, Indiana and so far none of them are leafing out this spring (4-28-14) Do you think that this past winter could have killed then?
view the full question and answer

Problems with non-native parsley from Brooklyn NY
June 17, 2012 - Had beautiful flat leaf parsley plants recently turn yellow & die. Found black armadillo like bugs bored throughout the roots. Now they're spreading. How do I kill them without contaminating the pla...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
© 2015 Lady Bird Johnson Wildflower Center