En EspaÑol

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
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

Tuesday - July 17, 2007

From: Pensacola, FL
Region: Southeast
Topic: Diseases and Disorders, Trees
Title: Juniper as host of cedar-apple rust
Answered by: Nan Hampton

QUESTION:

Thanks for the helpful advice on the Eastern Red Cedar. I was wondering if you could ease my mind about a potential problem. I have read up on some of the native plants in my area in a very good book " Florida's Best Native Landscape Plants" by Gil Nelson. In it, the author advises to not plant the Juniper (Red Cedar) near crabapple or haws (because the Juniper is a host of cedar-apple rust). I recently planted about a month ago 'Crataegus flava', or summer haw, in my front yard (the same area I want to plant my Red Cedar). My question is, what is cedar apple rust, and how close is too close to plant a red cedar in relation to my summer haw? Is there any precautionary measures that can be taken to prevent the cedar apple rust from occuring? If I moved my summerhaw to the backyard and planted the red cedar in the front yard, could this prevent the cedar apple rust? I am open to any of your suggestions. Thanks again for your helpful advice.

ANSWER:

Cedar apple rust, cedar hawthorn rust and cedar quince rust are fungal infections that require two hosts—a Juniperus sp. (e.g., Juniperus virginiana (eastern redcedar)) host and a host in the Family Rosaceae (hawthorns, apples, quinces). On the junipers the rust forms galls that contain spores that are then transfered, mainly by wind, to the rosaceous species. Junipers are not severely impacted by the fungus. They will have galls and some twig death may occur but the effect is mild. On the hawthorns, apples or quinces, however, the spores have a more deleterious effect. Spots form on the leaves that may brown and die and fruit may be severely infected.

The University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) says a distance of several hundred yards between the trees of the two species may offer protection. Ohio State University's suggestions for controlling the fungus include removing the galls from the junipers before they have time to ripen and spread their spores.

Mr. Smarty Plants would recommend that you move your summer haw to your backyard so that it is not in close proximity to your juniper. Then, watch your juniper for signs of galls and remove them as soon as they are found. This should offer protection against your summer haw getting the fungus.

 

More Diseases and Disorders Questions

Need help with yucca palm in New York City, NY.
November 10, 2011 - I have had my yucca palm plant for almost 10 years. The bark has started to peel off although leaves seem fine. The second smaller separate yucca plant has half its bark and trunk gone. I can't see a...
view the full question and answer

Yellow in pin oak leaves from Allen TX
May 25, 2012 - I have two pin oaks and one is completely yellow - a sign of iron deficiency and the other is starting to turn completely yellow as well. I've a proposal for iron deficiency but it is quite expensiv...
view the full question and answer

Leaves of non-native crape myrtle browning in Sinton TX
June 12, 2010 - Crepe myrtle – tips of leaves are brown and curling up.
view the full question and answer

Young oak damaged by falling tree from San Diego TX
June 27, 2012 - My neighbor's Palo Blanco tree was struck by lightning and fell over our fence and on to a young oak tree in our yard. We waited a few days to see if the neighbor would offer help, but he never did,...
view the full question and answer

Trees starting to die in subdivision in Hutto, TX
May 31, 2012 - I live in Hutto Tx, in a subdivision where everyone has the 2 trees planted in the front yard. My trees have started to die, and I want to find out what kind they are to find a solution
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