En EspaŅol
Share

Ask Mr. Smarty Plants

Mr. Smarty Plants - Possible mildew on standing cypress

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

Thursday - May 29, 2008

From: Austin, TX
Region: Mid-Atlantic
Topic: Diseases and Disorders, Herbs/Forbs
Title: Possible mildew on standing cypress
Answered by: Barbara Medford

QUESTION:

My mother-in-law took some standing cypress seeds from Texas to Virginia several years ago. They have always done very well, but this year they are growing very tall, but the bottom half of the stalk is turning silver. They have had 7 inches of rain recently. Is this a mildew? What can she use on it that won't hurt the hummingbirds?

ANSWER:

Ipomopsis rubra (standing-cypress) is native to both Texas and Virginia, so there is certainly no reason why it shouldn't do well in your mother-in-law's garden. Your description sounds like there could be a mildew problem. Read this article from Ohio State University Extension on Powdery Mildew on Ornamental Plants. One point the article makes is that mildew is rarely that dangerous a disease on ornamentals, and that powdery mildew fungi produce airborne spores and infect plants when temperatures are moderate (60 to 80 deg) and will not be present during the hottest days of summer. With any pest or disease, cultural controls are far better for the environment (including the hummingbirds) than chemical controls, which should be a last resort. Cultural controls for this plant would include making sure it is in full sun, not shaded, that it is not watered from above (of course, that's what rain does), and that the plants are far enough apart for good air circulation. As this plant is a biennial, it will seed itself at the end of the season, and the gardener should be sure to keep the seedlings thinned out as they come up.

You are probably correct that 7 inches of rain has not helped the situation. However, drier, hotter air is coming with the onset of summer, and the problem may resolve itself, or at least not damage the plants or limit the flowering. Standing Cypress can get quite tall, up to 6 or 7 feet, so it's worth taking the trouble over it. In the above link, you will find recommendations for chemical controls but, as said before, we much prefer the cultural practices that promote a healthy plant. Since we don't know what county in Virginia your mother-in-law lives, we can't give you a specific link to her county extension office. However, she can find them under "County Offices" or simply search on her county name and "extension office." That would be a far better source for recommendations on treatment of the mildew than anything we can offer from here.


Ipomopsis rubra

Ipomopsis rubra

Ipomopsis rubra

Ipomopsis rubra

 

 

More Diseases and Disorders Questions

Problems with lantanas in Austin
September 02, 2008 - Lantanas redux! I'm having similar problems with my Lantana here in Austin, Texas, as the person in Bandera. My husband has cut it back to the ground twice this summer. It returns, beautiful vibra...
view the full question and answer

Why are my lemon Cyprees trees turning Black?
April 01, 2010 - I have 3 lemon Cypress plants - all are about 6 feet tall. One of them has started turning black on one side - like it's been burnt. The inside of the plant is also turning black. I assume something ...
view the full question and answer

Agarita and Mexican Buckeye not flowering or fruiting.
December 11, 2012 - The Greenbelt behind our home has a ton of agarita and Mexican buckeye, but they never bloom or berry. The pigeon berry is very happily doing both all year. Any suggestions for helping the agerita a...
view the full question and answer

Problems with wax myrtle in Roanoke, VA
August 20, 2009 - Our Wax Myrtle bushes tend to lose all their foliage during the Winter months and each year seem to flesh out their leaves less with each passing Spring. One bush never returned and save for one branc...
view the full question and answer

Leafing out problems with oaks in Towson MD
June 02, 2012 - 3 native 5-year-old oaks kept old leaves until March and are not leafing by the end of May. The few leaves that have emerged are shriveled. WHAT'S WRONG?
view the full question and answer

Smarty Plants's Facebook profile Support the Wildflower Center by Donating Online or Becoming a Member today.

Mr. Smarty Plants wants you to be his Facebook friend. Click the Facebook icon to add yourself to Mr. Smarty Plants list of friends.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP
© 2014 Lady Bird Johnson Wildflower Center