Problem with Austrian Pine

Robb

Hi All... I live in the West Suburbs of Chicago. I had 3 seven foot Austrian Pines planted about 15 feet apart on the Southwest side of my house 5 years ago. They all did very well for the first 2 years, then the one in the middle began losing needles on the bottom and middle branches, and it's growth became stunted as compared to the other 2. The problem has become progressively worse since then as shown in my attached pics. I inspected it today and also noticed sap and possible dark mold or fungus running down the middle of the trunk. I'm wondering if this tree could still be saved or if I should remove it ASAP to prevent whatever is killing it from spreading to the other 2 healthy trees. Any insight anyone can give me pertaining to this problem would be greatly appreciated.

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laurelrsmith

I am sorry to hear about your Austrian Pine. Though I am by no means an expert, I have studied trees passionately as an amateur. Since there are many Austrian Pines in my area, I have studied their diseases a fair amount to account for unusual things I noticed.

I suspect from your description and your pictures that your tree is suffering from one of two fungal diseases that frequently infect Austrian Pines: Diplodia Tip Blight or Dothistroma Needle Blight. There are also a number of insect pests that can affect Austrian Pines, but your tree sounds and looks more like a fungal disease. Unfortunately, your description lacks the details to distinguish between these two diseases, at least with my lack of expertise, although one of the pictures makes it look more like Diplodia Tip Blight (which is the most common disease).

My suggestion is to google these two fungal diseases for more details (be sure just to enter the Latin names for searching). After further inspection you might be able to diagnose which disease it has (if not both). There are ways to treat the diseases and preventing further damage. However, your tree is probably never going to improve and regain its health and appearance. If it were me, I would have the tree removed ASAP to help prevent spreading of disease to the other trees. Then, keeping the beginning symptoms in mind, I would keep a wary eye on young shoots and cones for infection so that you can still save those trees.

Here is a helpful link for Diplodia: Diplodia Blight of Pines FIDL Diplodia pinea Here is a helpful link for three fungal diseases, including the main two discussed above: When Should I Spray Conifers for Needle Diseases? | Horticulture and Home Pest News

I hope this helps.

laurelrsmith

P.S. If you google "dipolodia images" and "dothistoma images" and follow the images to their source, you can find some very good information from universities and governmental sources. I had collected quite a list for you, but then I accidentally deleted my message containing the list. Apparently diplodia is extremely common in Illinois. That is the main thing I noticed in my research.

Also, the main difference between the diseases I have found is that in diplodia, the new needles are attacked. They are completely stunted and deformed. In dothistoma, on the other hand, it is not current year growth, but second-year growth that is affect, with the needles turning brown halfway down but remaining green in the inner half.

Apparently diplodia does not cause death directly, instead leading to attack by bark beetles that cause its death, whereas dothistoma appears to cause death itself.

Apparently both start from the bottom and go up. Both are caused by fungi, which can be detected by black fruiting bodies on needles, cones, and bark with a magnifying lens.

My suggestion is still to remove the tree to prevent the spread of spores, but make sure you don't do it in spring or early summer or in moist weather, as these are times when spores are most likely to spread.

Eric Frei

Great work laurelrsmith

I like it when information is referenced especially from Universities, colleges, govt .... it's trustworthy.

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Chimera

Diplodia reinfects the tree every spring from the overwintering litter (although some may overwinter in/on the plant). You can reduce the amount of infection by practicing good sanitation. That means sucking up/picking up any fallen needles or cones and burning them or moving them far away from any of you other Austrian pines. Pruning out infected branches will help too, but make sure you sterilize the pruner between cuts.

Brent Ferris

I generally find once a branch has been infected with Diplodia, that branch stays infected until death(unless treated). A branch only has 4 -5 years worth of needles on it, and since Diplodia kills the present year's growth, within 4 years, that branch is dead. Diplodia is easily recognized by short dead needles at the tip of the branch. Austrian pine needles are typically 4 inches long, dead needles are usually 2 inches or shorter.

It spreads by spores - best in damp windy weather, easily spreads within the tree and between trees., Its effect can be minimized, by cutting off the diseased tips -- dipping the pruner in 50% bleach/water with every cut, and painting the cut ends with 50% bleach/water mixture -- and with great diligence, can sometimes stop the disease -- locally ie your trees.

Sanitation, as mentioned is crucial to minimizing re-infection., But since the trees were infected from another tree, and spores can travel up to 2 km you need to check if there are other infected trees in your area, and get them treated/removed. If they are neighbours' trees, this is unlikely.

Yearly maintenance is essential to keeping all trees as healthy as possible.
Definitely remove the centre tree. All are competing for water and nutrients, and the middle one is suffering most -- and many would say its poor growing conditions has stressed the tree and made it more susceptible to succumbing to disease.

The loss of needles at the base, and the centre of the tree is normal - lack of light.

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My business: Tree Pruning and Removals -- Strump Removals -- Advice -- Consulting -- Arborist Reports
If you want an honest opinion, call Brent Ferris...because, Trees want to Live Too !
We do great jobs, even in small yards.

Free Estimates Oakville to Oshawa - North to Bradford (Will travel further if cost of travelling covered)

Robb

I'd like to thank everyone for their recent input. I think Laurel is righton her Diplodia diagnosis. I took some more pictures today that I hope will help confirm this. I'm very concerned about saving the 2 healthy trees, and it appears that at least the front tree also is infected, although it is in the early stage. The weather has been very damp in Chicago so I've been waiting till it dries out as suggested before removing the center tree and pruning off the infected branches on the other two.

I'm wishing now that I had done a little research before planting these trees where I did as the front tree already is getting crowded by the house. The nursery certainly should have advised against planting these here due to limited growth space. I'm considering transplanting the front tree (the one on the right in the pictures.) Can anyone advise me as to how wise it would be to transplant a 16 foot tree that's been in place for 5 years?

Thanks again for all your input and I will appreciate hearing what you all have to say after viewing the new pictures.

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Robb

The pics on my previous post are needles from the infected tree and a branch from the same tree.

The pics below show the proximity of the trees to each other and the tree I mentioned that I'm thinking of transplanting.

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Brent Ferris

Transplanting will work, but depends on size and access. I generally find stems over 2 inch diameter are difficult to successfully transplant by hand. Tree spade companies can normally move trees up to about 10 inch diameter, but there needs to be room for the spade (up to 8 ft in diameter) and the truck -- around 40 ft long. In our area, a tree spade will move a tree to another part of your your for $800 $1000.

Nurseries seldom give much advice about where to plant - partly because
people don't pay any attention -- "their needs are special" or if it doesn't work out, the people buy more plants -- keeps the economy moving.

Hard to be sure (uncertain if clump of needles is typical of dying branch) but pics don't suggest Diplodia. Need to see pics of tips of branches with dead needles.

__________________
My business: Tree Pruning and Removals -- Strump Removals -- Advice -- Consulting -- Arborist Reports
If you want an honest opinion, call Brent Ferris...because, Trees want to Live Too !
We do great jobs, even in small yards.

Free Estimates Oakville to Oshawa - North to Bradford (Will travel further if cost of travelling covered)

Robb

After comparing the pictures I took with pictures of dothistoma needle blight it appears that's what's ailing these trees. As for now it appears the only thing I can do right now is wait till it dries out a bit then remove the middle tree, then prune and rake up all the fallen needles that I can. From what I've read, fungicidal treatment should be done in mid May then again around the 1st of July. Thanks for the help everyone... especially Laurel, who diagnosed the problem.