Verticillium Wilt in a very well established Catalpa

[benlonghair]

Greetings folks. Found this site while trying to determine if my new Stihl MS 361 was a good purchace. (I've decided that I made a good choice for long term firewood cutting.)

Anyhow, that's not the point of this post. I've got a very large catalpa in front of my house here in north east connecticut. This tree is ~36"-40" at the base. I've been told it probably dates back to about 1860, which would make sense with the age of my house.

Earlier in the season we noticed it was losing A LOT of leaves. We first attributed it to the wierd shifts in weather we were seeing (flowered almost two weeks before normal this year.) Now I'm starting to see whole limbs dying off, leaves first wilting then turning brown while still on the tree. Leaves have started dropping again, although not as severe as eariler this summer.

In searching the net for what is wrong with it, I came across several articles mentioning Verticillium wilt, which is apparently caused by a fungus. I have been building a patio under the tree, but due to the size of stones and the fact that I didn't want to disturb the roots I opted to start at ground level and build up for stones that weren't as thick. There was very minimal root damage. (I don't think I ever cut a root that was bigger than my index finger or that was gowing anymore than 2" below the ground.)

I'm more than a little worried about the tree for a couple reasons. It's an amazing shade tree, for one. You can sit under it in all but the heaviest rain storms and not get wet for half an hour. The second reason for concern is the fact that if it were to become unhealthy and fall on it's own, it would only have about a 35-40* arc where it wouldn't destroy a building.

Here's my question. If, in fact, it has verticillium wilt, is there anything, short of cutting it down, that I can do for the tree? If I take off all the affected limbs it'll be about 60% of the tree.

Thanks for any help offered.

EDIT: If it will help I will post pics when I get home tonight.

 

[benlonghair]

I'm a forum troll on other forums, so I'm pretty well versed in posting pics.

It should also be noted that I have a (what I'm told is a female) Kentucky Coffee tree that's about 8' away (same approx size, been told that soldiers coming home from the civil war brought back seed pods as souvenirs) that has suffered no problems.

 

[treeseer]

There was very minimal root damage. (I don't think I ever cut a root that was bigger than my index finger or that was gowing anymore than 2" below the ground.)

Could be more than minimal.:jawdrop:

Are you sure the branches are dead? Late summer defoliation is not always a sign of branch death. Can anyone get up there and scratch the bark to find out?

 

[benlonghair]

Are you sure the branches are dead? Late summer defoliation is not always a sign of branch death. Can anyone get up there and scratch the bark to find out?

I would be less likely to worry about it if it were the whole tree. But it's not. Because of the positioning of the tree, only about half of the tree has branches/leaves on it to begin with as the canopy of the Kentucky Coffee and the Catalpa mesh together. The crown of the Catalpa seems healthy enough, from what I can see from the ground, it's the lower 2/3 of the tree that's looking bad.

I could get some down with a pole saw, I suppose. I'll pull down one of the lower poor looking branches and photograph the leaves, bark and inside of the branch when I post pics as well as an overview of the tree.

 

[benlonghair]

Ok, here's some pics. Battery died half way through, and, of course I don't have any more fresh ones. :angry2:

Hopefully these will shed some light on the issue.


This is a closeup (more or less) of some of the affected branches.

Here's an overview of the tree, showing both live and dying branches

More dead and alive

The butt end of freshly cut branches. Quality isn't great, but the smaller of the two is a healthy branch. They don't look all that different to my untrained eye.

Kentucky Coffeetree and the Catalpa, hopefully to give size perspective.

The patio. The stones are very large, therefore they sit above-grade. Screw digging them in. Only about half of them are new, the others have been there for about 2 years.

There's more involvement than I remember noticing a week ago. It seems to be getting worse. It'll break my heart if I lose this tree.

 

[S Mc]

Treeseer, I know that discoloration in branches is classic for Verticillium wilt. However, there might be other causal factors I am unaware of. Should she peel back the bark on the limbs for a look at the striation on the sapwood?

Ms. Benlonghair, how were the stones brought in? Those are extremely large and heavy, so I am thinking heavy equipment placed them. You could have compaction issues going on as well as the amount of roots affected. As Treeseer pointed out, you may have impacted more of the root system than you were aware. The tree's absorbing roots are in the top 12" of soil and are all smaller, sized roots.

Verticillium wilt is a soil born fungus and will become opportunistic to infection courts provided by the damage to the roots.

Sylvia

 

[benlonghair]

MR benlonghair, tyvm (That's mom helping me take the pics by holding the branches)

The stones were moved in with a bobcat. Basically we removed the turf and laid them on bare dirt. Again, we did not dig down more than an inch below the existing turf.

If you'll excuse my terrible freehand diagrams, I'll try to shed more light on the subject. First one is an overview of the area. When I say existing, I mean it's been there for 3+ years. (Driveway is 100+ years old. The front walk has been there for ~20 years.) I did my best to keep the scale as close as possible.

There is a fairly steep grade up from the driveway which the bobcat had to come up to drop the stones. I was amazed at the lack of damage that the skidsteer made on the lawn. It was literally pack it down, water it, and it looked untouched in a week.

This one more or less shows what I'm talking about.

The only time we have ever seen this type of behavior from this tree is when it got hit by a windsheer in the mid-80s. It lost a limb that was ~10" in diameter and (I've been told by an arborist) stressed the hell out of the trunk.

 

[benlonghair]

Are any weed killers being used to keep things down between the stones?

I do my very best to stay away from any kind of pesticide/herbicide etc. So no.

(Although I'd kill to find a way to chemically control bittersweet.)

 

[S Mc]

MR. Benlonghair. First please accept my sincere apologies!!! (The long fingers in the photo had me confused.)

The branches shown by your mother do have green cambium yet and therefore are still alive. However, this does not mean it is not fighting VW.
To rule out Verticillium wilt, you could call your local extension service and see if they offer a diagnostic service for this fungal disease. This would answer that concern.

The diagram you show (which by-the-by is REALLY a good one) illustrates a tree whose critical root zone has been/is being impacted on all sides. Add this together with added stressors from past events. Things may simply be adding up for this tree and its capacity to cope.

I would encourage you to get a definitive diagnosis.

Sylvia