Bacterial Wetwood| Slime Flux| Facts

Eric Frei · 10th May 2010, 10:02 AM

Information on wetwood and slime flux. also check PDF's attached.

Slime Flux - Plant Diseases - utahpests.usu.edu

Quote:

Slime Flux

Slime flux, often called bacterial wet-wood, is a bacterial disease found in many different types of trees. In some trees, particularly willow, this disease results in a white to gray foam that bubbles out from under the bark. In other cases, as with elm and cottonwood, infection results in wet gray to brown areas on limbs and trunk. In the latter case, the slime runs down the bark, discoloring plant tissues and resulting in a build-up of dry scum. Slime flux (wetwood) is a bacterial fermentation of tree tissue, resulting in the disagreeable odor associated with this problem.

The bacteria enter through open wounds in the bark. Wounds as small as cat scratches can serve as avenues of infection; however, more trees are attacked through wounds from improper pruning, boring insects, poor branch angles, tree houses, and lawn mowers. The latter can be avoided by replacing grass around the base of trees with a mulch of gravel or bark or remove grass with herbicides. Improper pruning wounds can be avoided by learning proper pruning techniques. Avoid topping trees.

There are two types of slime flux in Utah, the heartwood type and bark/cambial type. Each type needs to be discussed separately because the treatment is different for each.

The bacteria attacking heartwood result in the build-up of internal pressure up to 60 pounds per square inch. This can cause bursting of the infected tree, but more often the pressure forces the ooze out through cracks that extend from the heartwood (inner portion) to the bark surface. Flux runs down the tree trunk, killing the bark tissue it contacts. It also drips to the ground where it kills grass or other plants, leaving large yellowish, dead areas. Trees are rarely killed with this type of infection.

There is no cure for the heartwood infection that is common in elms, cottonwoods, and other poplar species. Drilling a hole in the infected area and inserting a plastic pipe to drain off the ooze can relieve the internal pressure. This prevents the unsightly slime from running down the trunk or killing the grass, but does not eliminate the infection.

Bark/cambial infections frequently result in death of the tree within 1-2 years. In willow, the bacteria tend to be limited to the tissue between the outer bark and the wood called the cambium. Fermentation produces the offensive odor and slime, but attempting to alleviate the problem by inserting a tube does not relieve the problem. If the fluxing is noted soon enough, the tree can be saved. Waiting and hoping the problem will correct itself often results in a dead tree.

Trees suffering from bark/cambial infections may be saved by promptly cutting away diseased tissue. On small branches it is best to prune the infected branch off at a lateral. With larger branches or trunk infections, remove all discolored bark down to the wood. Cut around the infected trunk or branch until you come to healthy, yellow-green cambium. In some cases this means removing a lot of bark. If the infection encompasses more than half of the trunk, it is probably best to treat with a chain saw at ground level and start over again with a less susceptible tree.

The next step consists of shaping the wound to allow it to heal properly. Remove infected bark creating an oval shape. The long part of the oval should be parallel with the trunk or limb. Make the margins of the cut smooth and clean. Sterilize the knife with rubbing alcohol between cuts to prevent spread of the bacteria.

The final step involved cleaning the wound with a disinfectant such as rubbing alcohol or a 10% solution of bleach (1 part household bleach and 9 parts water). Watch the treated area for evidence of recurring disease activity. If tissue on the edge of the wound begins to flux, a spot of diseased tissue may have been missed.

Heartwood Infections
Elm
Cottonwood
Poplar
Boxelder
Russian Olive
Ash

Bark/Cambial Infections
Willow
Mountain Ash
Aspen
Poplar
Fruitless Mulberry

BP-32, Tree Diseases

Quote:

Slime Flux

Paul Pecknold, Extension Plant Pathologist

During growth, trees can become infected with bacteria that inhabit the wood and cause a condition known as wetwood or slime flux. The bacteria infect trees through wounds caused by impact, pruning, or cracks from freezing or weak limb crotches. The bacteria may live within the tree for many years without any outward evidence that the tree is infected. Eventually gasses produced by the bacteria can cause the internal pressure of the sap to become very high.

Symptoms

As a result of high sap pressure, the sap oozes out of openings in the bark and runs down the trunk of the tree, causing dark streaks that then turn light gray or white upon drying. Oozing sap may be frothy at the point of exit. Airborne bacteria, yeasts, and fungi often colonize the wet oozing material, called slime flux, which it to ferment and smell very bad. Slime flux may delay wound healing (callus formation).

There are many trees in the Midwest that may develop slime flux. It is extremely common on elms; in fact, the majority of elms in Indiana have slime flux as a chronic condition. Slime flux is common on oaks and mulberry, and it may infrequently occur on maples (including box elder), paper birch, butternut, redbud, sycamore, and walnut.

Prevention

There is no control for slime flux. Inserting a drain tube into the tree to relieve pressure and drain infected sap was once an accepted treatment of trees with slime flux. This procedure is not recommended; it may do more harm than good. Boring holes in affected trees causes internal spread of the bacteria within the tree and allows entry of wood decay fungi.

Prevention consists of proper pruning of branches to allow rapid and sound healing; preventing other wounds to the trunk, branches, and roots is also important. Compacting soil around roots or disturbing root zones by installing flower beds around the base of trees creates wounds through which the bacteria can enter. Proper fertilization helps to invigorate affected trees.

treeshaveneeds · 10th June 2010, 12:11 PM

I have had a modicum of success treating heartwood slime flux by drilling a hole (sometimes a series of holes to find the bottom) at the base of the infection, and another at the top of the infection and dripping in a bottle of tea tree oil to kill the bacteria. 50% bleach and water also works, but the trees seem to be less bothered with the natural product. I have treated several elms this way, and the oozing and the spread to other parts of the tree has stopped. And, the clients were happy.

Eric Frei · 10th June 2010, 10:54 PM

Where you are ... does it kill trees if not dealt with?

Like how bad is this and what trees are likely to get it and die from it?

Where I am I have never had this, ever. What I read is conflicting about whether to drain or not to drain (in the PDF's).

I know we do not drain crotches or hollows that puddle anymore.

treeshaveneeds · 11th June 2010, 05:08 PM

Quote:

Where you are ... does it kill trees if not dealt with?

Like how bad is this and what trees are likely to get it and die from it?

The trees that get slime flux the most, (in this neck of the world) and if not die from slime flux, at least degrade so much in vigour their life is shortened considerably, often by decades - are the elms. I have treated white elm with most success, probably because the trees are bigger, and people want to keep them. Whereas Chinese and Siberian elms (U. parvifolia and U. pumilia) are considered more weed trees with a shorter life span, and peoples' attitude is the tree won't live much longer even if I save it, so let it go.

Quote:

What I read is conflicting about whether to drain or not to drain (in the PDF's).

I'm sorry, I haven't yet read the PDF's. I suppose you wouldn't have to drain the infection, but it would be hard to drip in an antibacterial agent if it had no where to go but slowly mix with the solution in the tree. By draining the infection, the amount of the toxic fluid is greatly reduced, and the likelihood the anti bacterial agent will do its job successfully is increased tremendously.
Of course, if several holes need to be drilled to find the bottom of the infection, this could easily add to more rot in the tree. Myself, if I had the choice of 2 or 3 holes being drilled in my leg to save the leg and my life, or cut off the leg to save my life, I would go for the holes, and then treat the holes. I expect trees feel much the same way.

Quote:

I know we do not drain crotches or hollows that puddle anymore.

There is little point draining these areas, unless the client insists. Because if the client wants the area drained, I would much rather insert a plastic tube and allow drainage, then leave the solution up to the client.. A lot of people around here still think filling a hollow with concrete is the way to go. And cutting a tree down with concrete in it is a real pain for filing. Presumably, by your comment, Aussies are more sensible than Canadians.

treeshaveneeds · 13th June 2010, 04:01 AM

After reading the 3 PDF's I suppose some of your confusion comes from drilling or not drilling.

If you drill, you could break thru the compartmentalization barrier and possibly introduce a way for decay fungi to enter the tree.

So how likely is that? The spores of most of these fungi are windborne - if there happens to a convenient drilled hole for the spore -- great! (for the spore) but if not, there are often branch breaks, woodpecker holes, bark damage, borer holes to infect. And it is not like once there is a hole, a big vacuum appears and sucks the spores in.
Would the oozing bacterial goo be more likely to trap a spore -- maybe, and could the spore travel into the tree as gaseous pressure is pushing out -- seems highly improbable. It is unlikely the pH of the goo would affect the spore -- but I don't know. I have never tested the foul smelling stuff for pH. Maybe I should start.....
If the tree gets infected with spores, there's a high likelihood the tree was already under stress from other factors - competition, pollution, water stress, heat stress, running out of growing space etc. I know if my leg was swollen up from an infection, and the doc said "we don't want to lance it, we could allow other bacteria in, let's let your immune system handle it" I would go home and lance the damn thing, squeeze out the infection, and then pour some tea tree oil onto the area to disinfect the surface and enter into my system to kill the inner infection, and give my immune system a fighting chance.

Most of the people writing the articles might well be well schooled in pathology, but how many have actually tried to help a tree? THe advice to leave the infection, and let it run its course, and eventually affect the phloem tissues and xylem tissues killing the top and then the roots - means they don't care about the tree (or there are too many, and no budget) or are afraid to act. It usually takes a good many years for wetwood to kill a tree. But, even if you are not willing to drill, then eliminate the other factors of stress for the tree, and give it a fighting chance to overcome the effects in its own way.
The problem with this advice is cost and practicality. For example: How do you minimize the pollution a tree receives? How do you stop salt spray, or pesticides, or fertilization with inorganic salts? How willing are you to counteract root strangulation - a really tedious job!! ? If you can actually do something about all these, you have the where-with-all to make an impact on the wetwood,

Practically speaking, if you want to minimize the effect of an infection on the tree, you have to help the tree get rid of the infection. So, drilling holes (need to ascertain bottom of infection, so more than one hole is necessary -- you can always plug "dry" holes) at an upward angle, and inserting a plastic pipe (more for future removers) so the infection can drain is a good start. But, all you get is a dribble. If you really want it to drain, you need to drill some holes at the top of the infection (at a downward angle) and eliminate the vacuum effect. And then, then you have the opportunity to help the tree more. Then, you can drip in an antibacterial solution into the tree. (like bleach and water, or tea tree oil, or oregano oil etc) And if it starts coming out, there is a good chance a lot of the bacterial goo has drained, residual goo is being neutralized and getting rid of it as well. So then (after it has pretty much drained) you could add more antibacterial fluid, and as it is coming out, plug the hole. Add more, top it up, until the bubbling of air thru the fluid stops, and plug that hole. And with some luck - assuming the tree isn't suffering other problems -- the tree will continue to thrive.

Yes, the tree will have holes in the trunk, and a big area where a defunct (hopefully) bacterial infection festered, and the tree will have to sacrifice a number of tissues to contain these intrusions. But if the tree is healthy - this should be no problem, and health can continue to escalate.

The trees I have found affected by wetwood in my area are mostly elm. Mulberries, poplars, occasional maples and willows - are also affected, but most of these are not considered high value trees, and so little effort is expended doing something about the wetwood. I have never seen wetwood affecting a conifer. Conifers do get areas of wet wood inside them - but these are usually from cracks in the trunk, or are accumulations of resin. The idea that wet wood forms, and then the bacterial infection? is someone not thinking the process thru -- in my opinion.

I hope this answers some of your concerns Ekka. If you have more, I'll see what else I might be able to shed light onto.

Eric Frei · 14th June 2010, 12:41 AM

Some good pictures of an oozer would be great too.

TrevMcRev · 14th June 2010, 12:56 PM

I've seen this in a number of Elms here in Melbourne.

Also, not mentioned in any articles i've found is Liquidambar, i've seen it more in this species than anything else.

I've done a lot of searching on this and never found any real solution, but lots of conflicting ideas. Many of which seem out of date & unlikely to be based on anything scientific.

Quote:

The next step consists of shaping the wound to allow it to heal properly. Remove infected bark creating an oval shape. The long part of the oval should be parallel with the trunk or limb. Make the margins of the cut smooth and clean. Sterilize the knife with rubbing alcohol between cuts to prevent spread of the bacteria.

If they believe that trees "heal" how correct is anything else they are saying....

10th June 2010, 12:11 PM	#2
treeshaveneeds Veteran Heritage Status Join Date: Jun 2010 Location: Toronto, Ontario, Canada Posts: 1,399	Re: Bacterial Wetwood\| Slime Flux\| Facts I have had a modicum of success treating heartwood slime flux by drilling a hole (sometimes a series of holes to find the bottom) at the base of the infection, and another at the top of the infection and dripping in a bottle of tea tree oil to kill the bacteria. 50% bleach and water also works, but the trees seem to be less bothered with the natural product. I have treated several elms this way, and the oozing and the spread to other parts of the tree has stopped. And, the clients were happy.

10th June 2010, 10:54 PM	#3
Eric Frei Admin - Razor sharp and independent 2 X Diploma Level 5 qualified arborist Join Date: Jan 2007 Location: Brisbane Posts: 12,820	Re: Bacterial Wetwood\| Slime Flux\| Facts Where you are ... does it kill trees if not dealt with? Like how bad is this and what trees are likely to get it and die from it? Where I am I have never had this, ever. What I read is conflicting about whether to drain or not to drain (in the PDF's). I know we do not drain crotches or hollows that puddle anymore. __________________ Protect your rights to work - Join Australian Tree Association My businesses:- Qualified Brisbane Tree Lopping \| Stump Grinding Brisbane \| Brisbane - Gold Coast Consulting Arborist

13th June 2010, 04:01 AM	#5
treeshaveneeds Veteran Heritage Status Join Date: Jun 2010 Location: Toronto, Ontario, Canada Posts: 1,399	Re: Bacterial Wetwood\| Slime Flux\| Facts After reading the 3 PDF's I suppose some of your confusion comes from drilling or not drilling. If you drill, you could break thru the compartmentalization barrier and possibly introduce a way for decay fungi to enter the tree. So how likely is that? The spores of most of these fungi are windborne - if there happens to a convenient drilled hole for the spore -- great! (for the spore) but if not, there are often branch breaks, woodpecker holes, bark damage, borer holes to infect. And it is not like once there is a hole, a big vacuum appears and sucks the spores in. Would the oozing bacterial goo be more likely to trap a spore -- maybe, and could the spore travel into the tree as gaseous pressure is pushing out -- seems highly improbable. It is unlikely the pH of the goo would affect the spore -- but I don't know. I have never tested the foul smelling stuff for pH. Maybe I should start..... If the tree gets infected with spores, there's a high likelihood the tree was already under stress from other factors - competition, pollution, water stress, heat stress, running out of growing space etc. I know if my leg was swollen up from an infection, and the doc said "we don't want to lance it, we could allow other bacteria in, let's let your immune system handle it" I would go home and lance the damn thing, squeeze out the infection, and then pour some tea tree oil onto the area to disinfect the surface and enter into my system to kill the inner infection, and give my immune system a fighting chance. Most of the people writing the articles might well be well schooled in pathology, but how many have actually tried to help a tree? THe advice to leave the infection, and let it run its course, and eventually affect the phloem tissues and xylem tissues killing the top and then the roots - means they don't care about the tree (or there are too many, and no budget) or are afraid to act. It usually takes a good many years for wetwood to kill a tree. But, even if you are not willing to drill, then eliminate the other factors of stress for the tree, and give it a fighting chance to overcome the effects in its own way. The problem with this advice is cost and practicality. For example: How do you minimize the pollution a tree receives? How do you stop salt spray, or pesticides, or fertilization with inorganic salts? How willing are you to counteract root strangulation - a really tedious job!! ? If you can actually do something about all these, you have the where-with-all to make an impact on the wetwood, Practically speaking, if you want to minimize the effect of an infection on the tree, you have to help the tree get rid of the infection. So, drilling holes (need to ascertain bottom of infection, so more than one hole is necessary -- you can always plug "dry" holes) at an upward angle, and inserting a plastic pipe (more for future removers) so the infection can drain is a good start. But, all you get is a dribble. If you really want it to drain, you need to drill some holes at the top of the infection (at a downward angle) and eliminate the vacuum effect. And then, then you have the opportunity to help the tree more. Then, you can drip in an antibacterial solution into the tree. (like bleach and water, or tea tree oil, or oregano oil etc) And if it starts coming out, there is a good chance a lot of the bacterial goo has drained, residual goo is being neutralized and getting rid of it as well. So then (after it has pretty much drained) you could add more antibacterial fluid, and as it is coming out, plug the hole. Add more, top it up, until the bubbling of air thru the fluid stops, and plug that hole. And with some luck - assuming the tree isn't suffering other problems -- the tree will continue to thrive. Yes, the tree will have holes in the trunk, and a big area where a defunct (hopefully) bacterial infection festered, and the tree will have to sacrifice a number of tissues to contain these intrusions. But if the tree is healthy - this should be no problem, and health can continue to escalate. The trees I have found affected by wetwood in my area are mostly elm. Mulberries, poplars, occasional maples and willows - are also affected, but most of these are not considered high value trees, and so little effort is expended doing something about the wetwood. I have never seen wetwood affecting a conifer. Conifers do get areas of wet wood inside them - but these are usually from cracks in the trunk, or are accumulations of resin. The idea that wet wood forms, and then the bacterial infection? is someone not thinking the process thru -- in my opinion. I hope this answers some of your concerns Ekka. If you have more, I'll see what else I might be able to shed light onto.

14th June 2010, 12:41 AM	#6
Eric Frei Admin - Razor sharp and independent 2 X Diploma Level 5 qualified arborist Join Date: Jan 2007 Location: Brisbane Posts: 12,820	Re: Bacterial Wetwood\| Slime Flux\| Facts Some good pictures of an oozer would be great too. __________________ Protect your rights to work - Join Australian Tree Association My businesses:- Qualified Brisbane Tree Lopping \| Stump Grinding Brisbane \| Brisbane - Gold Coast Consulting Arborist

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