En EspaŅol

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?


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

Saturday - January 29, 2011

From: Palm Beach Gardens, FL
Region: Southeast
Topic: Non-Natives
Title: Black fungus on non-native ixora from Palm Beach Gardens FL
Answered by: Barbara Medford


We have 7-8 ixora plants that are side by side and all have developed a black fungus or substance on them. The substance is not only on the plant, but has spread to the wall they are adjacent to. Can these plants be salvaged?


Ixora coccinea is native to tropical Southeast Asia, including India and Sri Lanka, and is therefore out of our range of expertise. The Lady Bird Johnson Wildflower Center is dedicated to the growth, propagation and protection of plants native not only to North America but to the area in which those plants are being grown. This Floridata article will give you more information, but does not mention a disease such as you have described.

This sounds like a sooty mold, which can often be caused by mold growing on the honeydew exuded by aphids. However, we are not sure if that mold would spread to a wall. This article Floridaplants.com has information on pests and diseases of Ixora coccinea. Of special interest in your situation is this excerpt:

"Insects and Diseases - This plant is subject to nematodes and should be mulched heavily. It is also attacked by aphids, mites and scale, which cause sooty mold."

If the plant, and especially the wall behind it, are not getting enough sun, the possibility of a mold gets higher. We suggest you examine the plant for aphids, and go from there. Please read this previous Mr. Smarty Plants answer which points out that the honeydew and the resultant sooty mold can spread to surfaces around the infested plant.






More Non-Natives Questions

Source for non-native, invasive Winter Honeysuckle from Austin
April 24, 2013 - Seeing Lonicera abiflora today reminds me of the "winter honeysuckle" my grandfather grew in San Antonio from 1920s or so through the 1950's. It was a bush with stiff upright stems and bloomed cre...
view the full question and answer

Growing non-native grapefruit from seeds from Austin
April 30, 2013 - Can you grow ruby red grapefruit trees from seeds?
view the full question and answer

Replacement for non-native wisteria in Temecula CA
December 08, 2009 - We recently moved into a house that has a Wisteria bush that has taken over the patio cover. I wish to take it out because it is so messy and looks bad when it is dormant. I am trying to figure out ...
view the full question and answer

Non-native Jacaranda interfering with concrete wall from Los Angeles
August 17, 2011 - We have been replanting the area surrounding our 2 story apt bldg and on one area, there is Jacaranda that started growing in an enclosed cement block wall area. The cemented walled in area which is ...
view the full question and answer

Is Viburnum dilatatum 'Henneke' (Cardinal Candy) toxic to horses?
July 01, 2014 - Is Viburnum-Cardinal Candy/Viburnum dilatatum 'Henneke' reported to be toxic or non-toxic to horses?
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.
© 2015 Lady Bird Johnson Wildflower Center