Splitting trunk and mildew

[lovespring]

Hello, I'm new to this so maybe someone can help me out.
Moved into this house about 2 years ago and there is what I'm sure was once a beautiful Lilac Tree in the back yard that's about 15-20 feet tall. Well looking at it now, it's not doing so well, I noticed that one of the trunks is split almost to the ground and it's growing what looks like mushrooms in the split. It does have new shoots and some new blooms off it but I'm afraid it wont last long. Is there something I can do to save this tree??

[opabinia51]

Well, mushrooms are just the fruiting bodies of some sort of fungus that is opportunistcally growing on the plant and probably eating it. I would remove them right away.

[lovespring]

Thank you,, I was removing some of them earlier, do you have any suggestions on what to do about the trunk splitting? The branches just break right off that section with no force at all, I was hoping it wasn't too late to save it.

[opabinia51]

My initial idea would be to use something like beeswax to seal the trunk. Be sure to get rid of that fungus and wash the trunk thoroughly before sealing it.

[The Helpful Gardener]

I disagree entirely with Opa here. Fungus on wood means dead wood and there is no point saving dead wood. I would do a rejuvenation prune on this tree immediately to take advantage of spring growth and cut off that whole trunk. You will lose the mass of the tree for a while but the surviving root system will shoot LOTS of new advantitious shoots that will flower much better and keep the plant healthy. A fifteen to twenty foot lilac is a clear sign that someone does not know how to prune this shrub.

If it is indeed a Lilac Tree (S. reticulatata) then I MIGHT follow Opa's course of action EXCEPT for sealing the wound (shown to create an extra surface area to collect bacterial or fungal colonies). But I doubt it. I run across this tree rarely. Does it have creamy white flowers long after the other lilacs are done?

HG

[lovespring]

I was considering how to remove the dead portion of this one, it has multiple trunks and the dead one is in the middle. I started trimming off the top to try and tame it a bit. As far as the flowers, it blooms a purple flower that doesn't seem to last all that long and that's it.

[opabinia51]

I'm really curious as to the reasoning behind seeing fungus on bark/wood means that the plant is dead Scott? From my experience, fungi will grow opportunistically on just about anything but, it does mean that the thing that is growing on is necessarilly dead.

However, I do agree with your methodology. That would also work. (and probably better, if I interpret it correctly)

[The Helpful Gardener]

My experience with wood is generally if there are mushrooms (of most types; there are some of those scallop-shaped numbers I see on healthy bark) on wood, it's dead...

Why do you get fairy rings in lawns? I will guarantee there is a dead tree buried under that exact spot. What do you grow shitaake musrooms on? A log. I don't know why mushrooms and dead wood get on, but they sure do...you're the soil guy, you tell me...

HG

[opabinia51]

Hmmmmmmm, I shall do yet even more research. (The story of my life ) Oh well, I do enjoy doing research. I want a definitive answer for this question.

It only took me 6 years to find an answer to the seaweed nutrient question, I wonder how long this one will take. Hopefully, I won't have to do any experimentology for this one!

[opabinia51]

Well, it only took me less than 24 hours. The answer is: that if you have fungi growing on your tree, then your tree isn't necessarily dead. It could be, or it might not me.

Here's the skinny:

What seems to be the most damaging fungal infections of plants are fungal vectors that are transferred to plants by insects. With Picea abies and Abies spp (Norway Spruce and True Fir) wood wasps intoduce fungi into damaged wood via exuded sap from wounds in the tree. The wasps are attracted to the sap and fungi are introduced into the tree from the waps bodies (presumably).

Now, in this particular study; researchers examined wounds on trees that were up to 24 years old and had fungal growths inside the trees with wasp larvae growing in the fungal (for lack of a better word: tubes).

Anyway, I don't want to review the entire article but, here is a fundamental rule of thumb in biology: A parasite is only a good parasiteif it does not actually kill it's host.

I mean, that would make sense, if a fungus killed it's tree host, then it would probably die as well or at very least have to find a new host.

With regard to fruiting bodies (aka: mushrooms). Well, mushrooms are not the only way that fungi as whole disperse themselves but, if you have fruiting bodies growing on some wood, it does not mean that the wood is dead, it means that the wood is infected and the fungus that has infected the wood is reproducing.

Now, the study that I have been quoting does make note that the heartwood of the plants was eventually damaged or destroyed so yes, death is often emminant if something is not done to curtail the disease (and plants can do this (refer to the post on Secondary Metabolites (terpenes). Anyway, overtime severe damage can occur. Best to nip the problem at the bud when you first noticed a problem

With regard to the above mentioned Lilac, Yes an excellant way to stem the spread of this fungus would be to cut away the infected areas and bud out new shoots. But, the infected areas are not necessarilly dead, what most likely happend is that when the tree was damaged, it exuded some sort of sap to put a "band aid" over the wound which attracted some sort of insect deposited the fungi or perhaps the fungal spore in the air stuck to the exudant and the fungus started assexually reproducing (growing) and voila, there is your mildew.

[The Helpful Gardener]

Thank you Opa.

Lovespring, is it a S. reticulata?

[url]https://www.colostate.edu/Depts/CoopExt/4DMG/Trees/trelilac.htm[/url]

HG

[opabinia51]

Your welcome Scott, you'd be amazed how much fun I had reading all the articles, really interesting stuff. I have actually checked out two books on the topic of plant fungal infections which I am currently reading and I've started a binder that currently has 5 articles in it.