View Full Version : Tree problem - fungus? bugs? (pictures included)

04-20-2010, 10:29 PM
In working with various landscaping I am hoping some of you here have some tree experience.

Below are some pictures of a "Valley Oak". These are a protected tree in my local area (central valley of CA) and are typically very hardy. This one was very healthy and actively growing when suddenly about 3 months ago we started noticing some bark issues around the base of the tree. As you can see from the below pictures the bark issues have progressed to the tree itself and the roots. We never see any bugs on this tree. I took these pictures today after having an arborist from the area come look at it. His comments were 1) the tree has a problem and 2) don't know what it is and 3) should probably take it out. I was thinking more along the lines of trying to fix the problem before it got any more serious, not remove the tree.

Any suggestions? Or perhaps somewhere else on the web you could suggest I find tree help?

More information - the tree does not get any supplemental watering. The bush to the right of it does get some water throughout our hot summer but nothing that really saturates the ground. The pictures show some moisture because I took them today after a full day of rain. Normally the soil is fairly dry.

Thanks for any help.


04-20-2010, 11:25 PM
I'm only going to take a guess. I'm thinking Crown Rot. and most likely caused by mulch being placed around and above the Crown of this tree. I'm also going to say...there does not appear to me as if there is any way to save it. Your best course of action in my opinion is to take it down.

Az Gardener
04-21-2010, 12:02 AM
I am not sure of the term crown rot, as crown usually refers to the top of a tree but I believe the diagnosis is correct. Looks like the soil or mulch was piled too high on the root flare and it rotted.

Root and trunk are two completely different types of tissue. Trunk is not supposed to be below grade. You need to be able to see the root flare, if it is buried too deep the tree will begin to decline and eventually die.

You can do a knock test and see how much of the cambium has rotted away. Just go up a few inches and begin knocking, go around the tree knocking and the hollow sound will let you know where the cambium is gone and it will not grow back in my experience.

I have seen trees last quite a few years with just a few inches of cambium left, but that was on desert tress.

The top looks good but I can't tell how much structural damage has been done. You are liable if it falls on somebody.

04-21-2010, 08:40 AM
The Crown of a tree is the area where the root system meets the trunk of the tree. It should not be covered, and is the reason trees should be planted with the root ball top, even or slightly above the Grade. Often when people add top soil, they will let it go higher around the tree, as well as surrounding area. This is a bad practice, and some sort of retainer should be placed around the crown, to prevent this rot from happening.

Here in New Jersey, it will not be too much longer before we see plenty of it. As many landscape Co's install what I like to refer to as Jersey Volcanoes. They tend to pile mulch very high up the trunks of the trees.

This area of a tree needs to be able to dry out, & not stay wet. The high pile of mulch tends to hold the moisture in there, and causes what is like Athletes foot to people. Think of "Trench Foot" during the first World War. Soldier's feet would not dry out and they rotted, sometimes rotted off.

In my opinion, that tree is dieing, There is a huge wound there at a critical point of the tree, There is no flow of nutrients and water above that open area, and it will decline. That area is now wide open to Insect and Disease invasion. It may last a few years, but I don't think it can be saved.

04-21-2010, 12:12 PM
Thanks for the replies, much appreciated.

I am sad to hear that the tree is probably doomed.

Anything I can do to minimize the continuation of damage? Minimize the spread? The other side of the tree when we dug down still showed healthy roots and the tree trunk itself still sounds very solid. I realize eventually this tree will probably come down but I was hoping to prolong that as long as possible. The tree is leaning away from my house and if/when it falls should just land in my driveway.....it may damage the fence but I can repair that. My yard is fully fenced and the risk of it falling on someone should be pretty minimal.....right now the tree still seems as solid as ever.

If this is something like a "rot" would removing some of that top soil around the base of the tree and putting in something like sand, that would drain well and stay dry, something that might reduce further damage?

Or should I get the chain saw out and get something else planted ASAP? One note on these valley oak trees.....before I can do anything they need to be city inspected, then a permit must be attained to even trim the tree, let alone remove it, etc.....

04-21-2010, 03:51 PM
You may fill the hole back in, and enjoy it as long as you can. But the issue is that all the water and nutrients flow between the bark and wood layer (Cambium) any interruption of the bark stops the flow above that wound. So nothing is going up the tree for the width of that wound. I don't know of anything that can replace that layer and return the flow, perhaps there is, but I am not aware of it.

Usually, we would fix it with a Chain Saw & Stump Grinder. Sorry. As I mentioned before, Damage like this is an open invitation to Insects, Borer's and such.

04-21-2010, 07:34 PM
Can I get a picture of the tree from a far distance that illutrates what it might hit if a failure did in fact happen.

The other posters are correct that something was brying this tree. It looks to me like it was planted too deep, and/or the grade was changed. I see no evidence of mulch from the pics, but doesnt mean it was added on too.

What are you using to excavate the soil? Hopefully no metal tools. These will only cause small nicks/cuts/scrapes in the bark and the tree will have to use precious nutrients to compartmentalize these wounds.

Excavate the rest of the root flare, take some more pics, and lets see what we can do for you with this. I wouldnt write off just yet.

04-21-2010, 09:13 PM
Just to point out what brings mulch to mind. It is the Landscape Fabric that appears to be pulled back, to facilitate the excavation of the root zone. The Fabric alone, could have been to tight around the base, as the tree grew bigger, Strangling it, causing this damage.

ICT Bill
04-21-2010, 09:27 PM
If you want to try to save it you probably can, build a well around it and expose the crown again. you are in a dry area with little humidity or bugs you "may" be OK

the grade has changed from when it was planted or it was planted too low to begin with. some dumas screwed up a really nice tree by covering the crown with landscape fabric and mulch. I'll bet when they were done they stood back and said how nice it looked............idiots

it may be gimpy and a little rough around the edges for the rest of its life. Hey you take what life gives

Dig a little passed where you are now and a foot or two from the tree and install 6X6's that allow the crown to get air and be aerobic. basically you are changing the grade so the tree can sit where it is supposed to and the surrounding area will be at grade as well

Once you expose the area to air the rot will have a very difficult time continuing, like others have said it may decline and have to be taken out but it worth a try if you like it

you can see the stress in the tree canopy......DO NOT use high nitrogen fertilizer on it, fish, kelp, humate would be fine. you want to nurse it, not grow quick

04-21-2010, 09:45 PM
Be careful excavating!!! You run th erisk of damaging the precious fiborous roots in this area, and drying out the others. airtools and a gentle experienced hand are best for this.

Az Gardener
04-21-2010, 11:09 PM
Put some dusting sulfer in the damaged areas to stop the rot and dry it out.

Just to clarify when you reduce the height of a tree by trimming, if done correctly, it is called a "crown reduction". So why would you call the root flare the crown? Is this a regional thing or did I forget my arborist training? It has been about 15 years. Just curious.

04-22-2010, 12:03 AM
Everything above the roots, is the Crown, this condition of rot at the intersection of the trunk & root mass, is called "Crown Rot."

04-22-2010, 12:16 AM
The junction between roots and trunk is the root crown; the disease there in question is crown rot. The top of the tree above the trunk where branching starts, and which describes a trees form, is the crown.

04-22-2010, 08:07 PM
There are 3 parts of a tree guys, roots, trunk, crown. The portion of the tree to which we are all looking at is the trunk flare, not root crown, not crown, not kings hat. Root flare is all.

here are some helpful links:






04-22-2010, 08:23 PM
As others have said, your only hope is to expose the root flair. Most trees come from the nursery already too deep...then are planted yet deeper. The fourth pic from the bottom shows where grade should have been...at the bottom of the root on the right.

04-25-2010, 12:20 AM
Thanks for all the great replies and discussion.

It looks like my choices may have been made for me. The arborist who we had come look at the tree informed us that he contacted the city and gave them information indicating that tree was unsafe and needed to be removed. Not sure if he felt he was doing us a favor or what, personally I wanted to try and save it.

We are waiting to hear from the city officials. According to the arborist now they will probably give us a permit to have the tree removed and give us so many days to have it done.

Just as a side note - I have 5 of these valley oak trees on my property. As far as we are aware none of them were planted by the previous owner but were native to the area/land when it was developed. Realize these trees are protected and literally numbered on the county/city registry (from what I have been told). In retrospect the grade may have been changed around that tree by the previous home owner, etc... to cause the problem but we only just noticed it in the last couple of months.

Thanks again for the discussion and information.