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

Friday - July 11, 2008

From: Portland, OR
Region: Northwest
Topic: Diseases and Disorders, Shrubs
Title: Leaf burn on hydrangeas
Answered by: Barbara Medford

QUESTION:

What causes my leaves to burn on my healthy hydrangeas?

ANSWER:

Our first thought would be too much sunshine, as the hydrangea thrives best as an understory plant with dappled shade. However, in Portland that doesn't seem like a big danger. Hydrangeas are susceptible to sunscald, chlorosis in alkaline soils, and winter dieback. Many weak, brittle canes are easily broken in wind and ice. Forms colonies from a shallow root system. Canes can be cut to the ground every two or three years to keep the shrub smaller, but if the canes are allowed to grow, the naturally peeling bark is attractive. Pest free. Prune immediately after flowering. There are three hydrangeas native to North America, but they tend to be more in the southern United States and none are native to Oregon. If it appears that the plant is getting too much sun, give it extra water, making sure it is not standing on the roots, and try to arrange a little more shelter for the plants next summer.

If that doesn't appear to be the problem, look at this Alabama Cooperative Extension article on Diseases of Hydrangeas. There are good illustrations of each of the symptoms of the various diseases, as well as suggested treatments. And you can go to this Oregon State University Extension page and try to find out if other similar plants in your area are being similarly affected.

 

More Diseases and Disorders Questions

Problems with hibiscus in Florida
November 09, 2008 - Have a hibiscus in Florida. It has always done beautifully planted in the ground. This year, it has developed something where the branches are sort of white, and the buds (and ends of branches) look ...
view the full question and answer

Ostrya virginiana Compatible with Juglone
May 17, 2015 - Is Ostrya virginiana sensitive to juglone?
view the full question and answer

Problems in non- native weeping willow in Spokane WA
June 21, 2010 - My wife and I have a weeping willow tree that has done well for two years. This year some of the branches are loosing their leaves in late spring in Spokane, WA. I though it was from the wind but ha...
view the full question and answer

Fungus Spots on Native Bush Honeysuckle
December 03, 2010 - My native bush honeysuckle plants that I have along my back fence have leaves that are turning yellow with spots. It appears to be a type of fungus, but not powdery mildew. Any suggestions as to what ...
view the full question and answer

Possibility of oak wilt in red oak in Austin
December 25, 2010 - I planted a Red oak tree in Austin January 2008. It was container grown but decent size, over 15ft tall. This summer (2010) its leaves turned color as if it were fall and started dropping. I starte...
view the full question and answer

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