Native Plants
![](../_images/smarty_plants.gif)
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.
Did you know you can access the Native Plant Information Network with your web-enabled smartphone?
Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.
![](../_images/mr_smarty_plants_logo_web_200w.jpg)
rate this answer
![](../_images/star_00.gif)
Thursday - June 20, 2013
From: Buckley, WA
Region: Northwest
Topic: Pests, Shrubs
Title: Spots on calycanthus petals from Buckley WA
Answered by: Barbara Medford
QUESTION:
Petals on calycanthus develop black spots the turn into holes. Problem appears shortly after buds open. Occurs every year. Foliage is healthy. Plant growing well and doubles or triples size every year. Has been in present location about four years.ANSWER:
There are two members of the Calycanthus genus native to North America. This USDA Plant Profile of Calycanthus floridus (Eastern sweetshrub) shows it growing nowhere in western North America. According to our webpage on Calycanthus occidentalis (Western sweetshrub) it is endemic to California. The USDA Plant Profile shows it growing only in Klickitat County of Washington, a couple counties away from you in Pierce Co., but we assume the climate, rainfall and soils are nearly enough alike that it will do all right in your garden.
From our webpage, here are the growing conditions for Calycanthus occidentalis (Western sweetshrub):
"Growing Conditions
Light Requirement: Sun , Part Shade
Soil Moisture: Moist
Soil Description: Moist soils.
Conditions Comments: Calycanthus occidentalis will develop leaf burn if planting site is too dry."
Please note the comment on leaf burn, if the site is too dry, as well as the need for sun (6 hours or more of sun a day) or part shade (2 to 6 hours of sun), but that is referring to leaves, and we assume you are finding the spots on the petals of the flowers. So, we will look further and see if we can find an explanation of the spots on blossoms.
Here is more information and pictures from Las Pilitas Nursery in California. From that, we learned that pollination is by members of the Nitidulidae family of beetles. Further research said that these are sap sucking beetles, and we could not find any indication that they did damage to flowers they were pollinating.
All the references we searched said that the plant was relatively pest and disease free. Since, as you say, the plants are healthy, we would not be too worried about it. We are native plant gardeners, not entomologists, but if you are concerned, you might contact the Washington State University Extension Office for Pierce County to see if other similar occurrences have been reported in your area.
From the Image Gallery
More Shrubs Questions
Need some help with a Plumbago plant in Mission, TX.
August 06, 2010 - Hello..I live in south South Texas and have a plumbago. It gets about 4 to 5 hours of direct sun and lately some of the branches and leaves turn bright green almost yellow. Am I over watering or is ...
view the full question and answer
Yellowing leaves on yaupon in Ft. Worth
April 23, 2009 - I planted a Pride of Houston Yaupon Holly in January in full sun. It is blooming little white flowers right now for spring, but a lot of leaves are turning yellow. Do you know what is causing this? ...
view the full question and answer
Further information on Melochia tomentosa in San Antonio
May 29, 2009 - Information in your database is limited for Melochia tomentosa. I would appreciate any further information you can provide such as requirements for sunlight, soils, water,etc.
view the full question and answer
Winter- and drought-resistant plant for North Central Texas
April 11, 2012 - I would like to know is there a good winter and drought resistant flowering bush for my area. I would like something with bigger flowers like azaleas or roses maybe bigger, that will not grow anymore...
view the full question and answer
Replacement for Amber Jubilee Ninebark in California
November 22, 2014 - AMBER JUBILEE bush separating my neighbor and me, is spreading its roots into our water pipes. Want to rip out. What plants are root friendly and also give you privacy?
view the full question and answer
Support the Wildflower Center by Donating Online or Becoming a Member today. |