black film on plants

[Dot]

Aloha gardeners, we've been seeing a black film on certain plants in Nanawale and Leilani subdivisions. Whatever it is, it's coating the plants with a black film, doesn't seem to be bothering the plants, but sure makes them look ugly. Any thoughts?

Dot

[leilaniguy]

Black mold.

[Dot]

That's what I thought, but why is it showing up now? I've been a part-timer for 9 years, this is the first I've noticed it this bad. Guessing Neem oil would clean it up, but there's a lot of it!

[glassnumbers]

does it look like this http://www.downgardenservices.org.uk/Sootymould.jpg

then its sooty mold. it's rarely fatal to the plants but it does make them look fugly.

Aloha

[Lee M-S]

I managed to clean up a small tree using a spray bottle with water and a little *non-ultra* dish soap. It took several applications.

*Ultra dish soap can remove the waxy coating from leaves, harming or killing the plant.

[Kenney]

2-3 applications of Neem 10 years ago changed our citrus from black to green. The mold never came back.

[EightFingers]

You probably have fire ants on those plants. They "farm" that white stuff, aphids and mold. It's a big food source for them. I had it bad on some foxtails. I sprayed with liquid copper and sticker solution and treated for the fire ants. No more mold, aphids or that nasty "white stuff".

[Clayjacks]

It's also called sooty mold. It grows on honeydew (read: excretia) from, most commonly, aphids, scale and mealybugs.
The mold itself isn't harmful unless it's really bad and interfering with transpiration or photosynthesis- in which case your plant is already doomed from the sucking insects. Try a hort oil, or soap, preferably on a cool(ish) or cloudy day, and focus on the insects rather than the mold.

[Dot]

Glassnumbers: yes, it looks like the picture, sooty mold.

My friends in Leilani have lived there for 30 years, they started seeing it about a year and a half ago. I noticed it on my Nanawale plants about the same time. My next door neighbor has a fire ant extermination business, so definitely not fire ants...one of the perks of having them for neighbors :-)

Maybe if it ever rains again...whatever bugs are causing it will drown! Mahalo nui loa for the input Punatics.