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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.

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Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

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Thursday - May 24, 2007

From: Dripping Springs, TX
Region: Southwest
Topic: Diseases and Disorders
Title: Rose canker in roses on cedar posts
Answered by: Joe Marcus

QUESTION:

While visiting the wildflower Center I saw that some of the plants were growing on trellis' made of posts cut from cedar trees. I made a trellis for my climbing rose bush and where the stems touched, turned black and the rose also turned black. Are there only a certain kind of plants that can climb my cedar trellis?

ANSWER:

It is likely that your roses were attacked by a fungal disease which gained entry through contact wounds caused by rubbing against the rough cedar bark. The likeliest candidate would be a disease called rose canker. Many roses, especially the non-native ones, are susceptible to a host of diseases. Pruning out diseased canes and using good cultural practices may be all that is required to rejuvenate your rose.
 

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