Pittosporum leaves black and sticky - Ask Extension
Hi I live in Australia (southern states, Melbourne) and have been growing three pittosporum trees in my wee back yard for 4 years to create a screen. ...
Knowledgebase
Pittosporum leaves black and sticky #506082
Asked November 27, 2018, 10:56 PM EST
Hi I live in Australia (southern states, Melbourne) and have been growing three pittosporum trees in my wee back yard for 4 years to create a screen. However the leaves have started going horribly black and speckly, some yellowing too (see photos). The decking under the leaves is also speckled with a very sticky substance that looks like dripping sap or something. The soil is shallow and pretty heavy clay, and they get a fair amount of sunlight most of the day, maybe 6 hours. Can you please help me understand what this is and if these trees are redeemable or have they had it!? :-(
County Outside United States
Expert Response
Thank you for your question. The following is a list of possible culprits: https://plantdiseasehandbook.tamu.edu/landscaping/shrubs/pittosporum/
However, as the following article explains, what might appear to be ‘sooty mold’ is an indicator of infestations of insects such as aphids, mealybugs, scales, etc.: https://plantpath.ifas.ufl.edu/media/plantpathifasufledu/factsheets/pp0029.pdf
Since I am unable to examine the plant for any of the symptoms of the above possibilities, nor know what chemicals are available for treatment, I suggest you contact your local horticulture school or reliable garden center for assistance. You can examine the plants for insects; a microscope might be necessary to identify a pathogen. Good luck!
Hi Kristena, thank you for this. Ive now looked into Sooty Mould and believe this is exactly the problem!! It seems this can be treated fairly easily, so hopefully all is not lost. Thank you so much for taking the time to get back to me. Fingers crossed I can now fix my trees and get them back to their former health. :)
You're welcome, and fingers are crossed!
