Black tar leaking from oak tree

automag928

Hello everyone! Hopefully this isn't a question that has been gone over time and time again...I tried searching on the forums, and wasn't coming up with anything so here goes.

I have 4 large oak trees in my yard, and one in particular has developed what looks like black tar running down the trunk and branches. In the one trail on the trunk, when you mess with the whole in the tree, little black ants go scurrying. I've included pics and would definitely appreciate any help!!

Thanks!

Trunk ---


Close up from above pic ---


Further up the trunk ---


Branch of the tree ---

wulkowicz

That's a Petrolius oblengatus whose roots have encountered a small underground oil pool. Some have been known to be productive enough to allow their owners to purchase a new fuel-efficient car.

There are some companies offering the kind of scam; selling a soil dipstick that would indicate future revenues. I'd avoid those as they are expensive and don't really provide as much information as the traditional oil stain on the basement wall.

Then again if you ask around, I rarely know what I'm talking about, so you will have to wait for somebody to give you a straight answer. It won't take long, this is an Oz site and they're straight as they come.

Tubbs



Okay I'm off preparing an apology; an explanation that I'm not being disrespectful; that I really meant to be funny in the middle of the night; and the nine guys with a water cannon should cancel the contract.

Urban Treecare NZ

Looks to me like bacterial wetwood or slime flux. Is usually resin that comes from injurys or old pruning wounds. It also can come from inclusions or co-dominant leaders (also known as tree farting). The bacteria latch onto it and turn it into the black stained colour. Aphids and ants feed on the liquid aswell. Kind of like powdery mildrew on citrus... hopes this helps

kiwi_tree_steve

Looks like slime flux to me, as far as i know its no major.

__________________
"You have to feel and touch a tree" Shigo

automag928

So from what I'm reading about slime flux, there is nothing to prevent it or cure it? And I'm not going to lose my beautiful oak tree?

TreeSpecialist

Not likely a slime flux but a "fungal" infection from Phytophthora cinnamomi. (Actually classified as a water mold.)

Common to red oaks. Can be dried up with Aliette® or Subdue® fungicide.

You're not likely to loose the tree. Turn off the water around the tree.

I don't know of a good organic product that will work.

As the disease progresses, the wounds weep a sweet sticky substance attractive to a variety of insects. The material will eventually ferment and smell rather foul.

__________________

treeseer

Yes at academic conferences i hear it called a "fungus-like organism". How sure are you that this infection is from that genus? If the flow is from a crotch 20' up, will a trunk/soil drench control it?

I would scrub the area, for looks and health.

TreeSpecialist

After working with red oaks weekly for 34 years with multiple independent lab confirmations, I'd be willing to bet on it.

With oak wilt a significant and well-known problem around here, folks see this problem in their red oaks and jump to conclusions, so frequent sampling is done to put their mind at rest.

With Phytophthora infections, we don't see the crown wilting and dying back - just the bleeding cankers.

Soil and root crown drench with Aliette® or Subdue® dry it up fairly quickly. Red oaks have relatively large vessels and take up material very fast. Trunk injections are also effective and can be absorbed in as little as 15 minutes with optimal conditions.

Scrubbing the area only will clean up the outside of the wound and won't stop the fluxing.

As a waterborne mold, the organism reproduces with a zoospore - a fungal- like spore with a flagella that moves it through the water stream.

Cutting back on irrigation or improving drainage is also crucial in treating this problem.

When trees look sick, most folks will water more - not less- before calling in the arborist. Our native red oaks do great with only rainfall.

__________________

treeseer

Great info; thanks much. I usually use phosphite for infections down lower, but the others sound worth a try.

Eric Frei

Very different to what occurs in Australia. Our trees get dieback.

Phytophthora root rot - fact sheet

More for you guys with ooaks, same disease, different symptoms.

IEFC - Forest pests and diseases - Consult - Quer-F-3

__________________