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

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

QUESTION:

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.

ANSWER:

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

Spacing of non-native crapemyrtle in Anniston AL
August 04, 2009 - We bought some Dazzle dwarf crepe myrtle bushes. We need to know how far apart to plant them. Thanks
view the full question and answer

Difference in native and non-native cherry laurel
October 02, 2014 - I have a backyard volunteer that I have identified as a cherry laurel, but how do I tell the Carolina from the non-native? This is still young (2 years or so), and not flowering, at least not now.
view the full question and answer

Pruning of non-native oxblood lilies from Austin
March 27, 2014 - My Oxblood Lilies flowered quite late last Fall. Their foliage is still very green. Can I cut it down now or do I have to wait until it goes brown?
view the full question and answer

Care of non-native Sorbaria sorbifolia (false spiraea)
August 24, 2010 - I have 2 Sorbaria sorbifolia (false spiraea) that will not flower. This is their third summer. What should I do?
view the full question and answer

Non-blooming crape myrtle in Italy, TX
June 25, 2008 - It's Italy, TX, again! Thanks for the advice and links, and I'll study those..but here's where I'm stumped on crape myrtle. I have two (almost) trees because they've been planted over 15 years ...
view the full question and answer

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