I believe the two trees we have at the end of our driveway are mugo pines. They are about 5' tall and wide and are in full sun. This year both of them...
Knowledgebase
Problem with mugo pine #750677
Asked May 18, 2021, 3:25 PM EDT
I believe the two trees we have at the end of our driveway are mugo pines. They are about 5' tall and wide and are in full sun. This year both of them are looking bad, lots of brown areas and missing needles, mostly on the north side. I am attaching some pics. Is this a fungal disease? Is there anything I can or should do about it?
Benton CountyOregon
Expert Response
The images are showing me the loss of needles from many shoots and branches of these pine trees. You are also showing us necrotic dead needles at the end of last year's growth. But I also see many new shoots emerging from those same branches and what you see as damaged areas. That is a good sign that they will recover from what ever is going on here. I do not suspect a disease of any sort. Especially when you say it is on the north side. I don't expect it to be any thing related to environment such as too cold or hot. What else is going on in the garden on that north side?
Thank you for your reply. It is reassuring. I didn't want to wait until it was too late to do anything if something needed to be done. I can't think of anything else to add. All the other plants in the area seem fine. I would suspect drought stress, except the south side of both plants doesn't seem to be affected.
On Wednesday, May 19, 2021, 06:33:21 AM PDT, Ask Extension <<personal data hidden>> wrote:
How about an image of the situation from a bit further back so I can see other issues that might be happening. Any construction on that side, change in irrigation, fertility applications, etc.....
Well, I don't see anything in particular. Maybe not too many weeds so did you use a herbicide that might have caused an issue? Other than that, drought could be an issue but Mugo pines don't like much water and you can get on the other side of that quick and encourage root rots. So, take care when irrigating.
I'm a compulsive weeder. No herbicides needed! My husband is in charge of watering. He doesn't particularly like these plants so they don't get watered. I'm sure the problem isn't overwatering. I will suggest that he give them a bit of water now and then.
Thank you for your help!
Vonnie
On Wednesday, May 19, 2021, 12:51:01 PM PDT, Ask Extension <<personal data hidden>> wrote:
I was walking the dog when I noticed the same symptoms in a yard for a house that is being sold (Withamhill area of Corvallis). There were 3 of these bushes in the front yard and all 3 were entirely bare of needles as you show for a few branches. New shoots emerging just fine. So I asked another plant diagnostician about this and here is his answer:
"Makes me wonder about a phenoxy herbicide application some time during warm weather last summer/fall. I’ve seen this before. Application is made when what is now last years growth is current season. As is the case with conifers, only the current season growth is affected. So, this growth receives this unintended herbicide and responds gradually over months to the exposure. Full symptom expression occurs months later in the spring with warm weather, which is what you see in the photos. That’s my guess."
His point is that a neighbor could have made the herbicide application and have it drift over to your plants. Difficult to detect or investigate if true. I am not entirely sure this fits your situation. In any case, lets watch how it grows and if needles begin to have issues we can re-asses the situation.
