Black sooty moldy? stuff covering leaves

[Dinamight]

Over the last 3 - 4 weeks a lot of the leaves on our palms have become covered in a black substance. I can scrape it off with my finger nail, it looks like dirt but the rain does not wash it away. It seems to have appeared quite suddenly.

Is this "sooty mold?" I haven't noticed a lot of ants around which I am told is responsible for spreading it. Is it dangerous to the tree? What should I be doing to stop it and get rid of it?

Thank you!

[tgalarneau]

Sounds like sooty mold. Neem oil or another oil will kill it and it is then easy to clean off. If left is will interfere with photosynthesis.

I have plenty, it is caused by fire ants farming mealybug and their honeydew then attracts the sooty mold. A nasty cycle that can kill plants.

Need to eliminate the ants as well as the sooty mold and whatever bug the ants are farming.

[Carey]

The "Garden Guy" at the Trib.Herald had a question (maybe from you!) on this same thing...and a kitchen recipe for an oil soap solution to spray on your plants!
link:
http://www.hawaiitribune-herald.com/sect...une-8.html

[Dinamight]

Carey and tg,

Thank you for your advice, it sounds like I can deal with it myself and it's not going to kill the plants before I have a chance to treat it and get rid of it.

It wasn't me who wrote to the Garden Guy, so it must be a common problem. I do read his column when I'm there but missed this one.

[pslamont]

Doesn't this sound like aphids? Granted they are usually found on fruit trees but still.... the soap solution should work if it is.

I want to be the kind of woman that, when my feet
hit the floor each morning, the devil says

"Oh Crap, She's up!"

[DTisme]

We have a mature Fiji fan palm with a bad case of crown droop. Hubby has sprayed it with oil/detergent solution and has fed it with a boric-acid fertilizer (which apparently is recommended for crown droop), but I fear it's a goner. We've been advised the safest thing is to remove the tree in case the problem spreads to neighboring trees. In the meantime, I've been told that power washing the sooty mold off trees can prevent this problem. The question is how. A friend swears by power washing his trees. He also removes all moss and lichens. Someone else told me to get a "tree scraper" that apparently look like giant cheese graters. Power washing, obviously, would be easier. Anyone have experience with this? The oil/detergent thing doesn't seem to help once it gets to a certain stage.

[Carey]

We scraped our fruit trees of bromiliads, lichen & such (we used a putty knife) & then hosed off the branches & leaves of the black sooty stuff a few years ago (our incoming hose pressure is ~145psi, so it is much like pressure washing). Trees were nice looking for a few years.

Last fall we noticed the black sooty stuff & a couple of bromiliads on the citrus & grape, & earlier this summer we used the oil soap recipe from the "Garden Guy" on a couple of our citrus trees & grape vines, after a little more than a month, new growth is nice & shiny & so much better looking... so last weekend I sprayed oil soap on everything.... did notice that it seemed to stop the LFA's from dropping on me from the palms (do not know if it was that I was oily soapy or what)

Will report later if this is a disaster or a miracle cure...

[Ryan.]

Thanks for the suggestions. I looked up the article online. Here's the recipe mentioned above. http://www.hawaiitribune-herald.com/sect...une-8.html