Losing Old Oak Trees

[Flyfishar]

I've discussed this on here a couple of times but a picture is worth a thousand words. We have roughly 40 acres and about 10 acres around the house. That acreage has roughly 200 large oak trees that a fair portion of have seen significant decline in the last 5 years. There is no real pattern to the loss such as high on the hill vs low, or big vs small, north vs south. Trees in the middle of otherwise healthy trees just simply die from the top down. However there is one area of the property where about 10 trees in close proximity have all seemed to die. The rest of the property seems to be losing trees in a random pattern.

I have called out a couple of different Arborists recently for opinions.One of them blamed the losses on Oak Borers (I didn't get a specific species). The other said it was a combination of both oak borers and a black fungus. They indicated that the black seeps on the trunk base were from the borers and the black fungus would rot out the roots and eventually kill the tree. Both of their explanations seemed plausible since the trees seemed to be having vascular issues and the tree tops suffered the most. Prior to them going they show thinning in growth at the top and lots of new growth on the lower end of the tree. The majority of the trees we are losing are 2-3 feet in diameter but we've lost some in the 4-6 foot in diameter as well which were really hard losses.

I have a few questions.

1. Is this an issue that will spread to the remaining trees?
2. Is there a treatment we should be applying?
3. We are removing the dead or dying trees. Is that enough or is there a reason to be more aggressive?
4. If it is oak borers is there a preventative treatment?

 

[Flyfishar]

 

[Flyfishar]

 

[Zale]

The borers are a secondary cause of death. The presence of borers are indicative of the tree being under stress. Are you going through a period of drought? Have you had periods of drought in the past? It is also important to know the exact type of borer that is present. This will determine type of treatment. Just a couple of thoughts.

 

[Flyfishar]

We are on the edges of the drought this year. We had one month of high temps and little rain but I watered all the way through it. This is something that has been happening for years though not just this year. We've had good weather for the last 10 years.

 

[Tree Pig]

Hard to tell from the picture but looks like you have some serious soil compaction also.

 

[Flyfishar]

Actually now that you mention it if anything we've had more rain than normal for the last 7-8 years. A couple of hurricanes came through here plus some really heavy frontal systems. Up until this year we've probably had maybe 20% more than normal rainfall totals.

One of the trees that is dying is even in close proximity to the septic field lines. Not in them but the drip line is maybe 15-20 feet from them which would at least keep it from totally drying out.



Stihl what do you mean by compaction? Are you saying the soil is pulling away from the root systems?

 

[Loraxguy]

oak Issues

How far dow in the soil profile is the water table?. Oaks don't like their roots wet

Borers that attack oaks in stress in my part of the country is the two lined chestnut borer. It's a cousin to the emerald ash and bronze birch borers. Very small d shape exit holes.

 

[Flyfishar]

The borer diameter hole is probably 3/8" +/-. It is more than a 1/4 and less than a 1/2.



Our soil is "mostly" red clay but has some sandy loam in it. It is mixed through out with chunks of limestone. Our soil drains well even though it has a lot of red clay. If we leave a water hose out the water will soak in before it can make it even 10 feet. I planted about 30 maples to replace the oaks we've lost. We dug holes 3x3x3 and all of them were fairly consistent in terms of soil. When we filled the holes and watered the trees the soil did not retain water or drain water excessively. I'd say it was fairly average.

There is a considerable amount of deep water. We live on a ridge / hill that is maybe 60 feet high. On the down slope side there are several springs that emerge from the side of the hill. The water is probably deeper than the general root systems but constantly runs. Even in our driest periods the springs still run strong. Not sure how deep oak roots will go but even in worst possible conditions there is water at 40-50 feet. If a tree can hit the springs it will have water in any conditions.

 

[Loraxguy]

oaks

the only other thing I can think of is a disease called oak wilt. Check with the local forestry people in your area and ask about oak wilt occuring? Oak wilt can spread by root grafts, along with insects.

 

[Flyfishar]

The trees do not defoliate which I had hoped would be a significant symptom. Leaves and limbs produce early then go dormant. Then they do not return in the following year. The trees die from the top down and eventually do not produce foliage and die.

Also the trees that are dying are randomly spread apart. The generally do not have root systems that are connected. It will be one large tree that dies in a group of 10 or 3 trees in a group of 20. With one exception all of the trees that are dying are just randomly dispersed.

 

[NCTREE]

looks like you may have some root rot issues. The mushrooms growing on the trunk and the rotten hollowed out root flares are indicaters. Lack of water and compacted soil can cause stress to the tree making it more susceptable to root rot.

 

[Flyfishar]

We have a steady replanting program going. In fact we planted about 30 trees this year. We're planting some diversity back though in lieu of just planting oaks. In fact you should see some 20 foot maples in the picture with one of the large trees.

I feel the same way about grass. :msp_angry: