Host an Event Volunteer Join Tickets

Support the plant database you love!

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

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

Red spots on white flower of Anemopsis californica
July 05, 2009 - Do you know what the red spots are on the white flower of the California native, Anemopsis californica? Is it a fungus, insect, or just physiological?
view the full question and answer

Live oak trees with rusty spots and holes on tree trunks
September 21, 2011 - I have live oak trees that have developed rusty spots, small holes on the tree trunks and sawdust on the trees base. They were planted in Oct 2010. We have had a hot dry summer in Texas this year an...
view the full question and answer

Bacterial spot in peach tree in McDade TX
February 05, 2009 - I have a Red Globe peach tree which was planted in February 2008. The local agricultural extension agent identified the tree as having Bacterial Spot in November 2008. They recommended copper hydrox...
view the full question and answer

Plants to grow in high zinc, lead and copper soil in Los Angeles
January 24, 2011 - We live on the Westside of Los Angeles and have just been given the bad news that our beds are high in zinc (86.39), lead (45.98) and copper(12.95). Can you recommend some plants that may grow in thes...
view the full question and answer

Problems with giant coneflower in Richardson TX
June 05, 2010 - Dear Mr Smarty Plants- I have had a giant coneflower in my garden for 2 years now. This year it came up like it always had..got lots of leaves and then withered..turned brown and died. It got plent...
view the full question and answer

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