What Could Be Making My Tree Brown?

August 18, 2016 11:33 PM

The other day I noticed that my tree is turning brown. What could the cause be? (linked photos)

I have a tree in front of my house that is turning brown on one side. I've tried Googling, but there are so few symptoms nothing seems to match. Here's a rundown of the details:

• This is the first year this has happened. There has been no new construction or other factors affecting sunlight, water drainage, etc.
• The needles on the outside are turning brown, but the needles closer to the trunk are not
• The browning is happening on the southwest side. There is another house immediately to the southwest, so while it gets southern sunlight, it gets far more southeastern sunlight than southwestern sunlight, and the east side is green as normal
• It's summer here, but not any hotter than any other summer has been
• There has been a little more rainfall than usual, but not a lot more
• There are no bugs, mites, pupae, worm tracks, or other abnormalities on the branches or trunk. Except for the needles being brown, everything looks like normal.
• I don't know when this started or how quickly it has progressed. I noticed it yesterday and my wife independently noticed it the day before yesterday. That could be coincidence, or it could be that it had a rapid onset, I don't know.

posted by Bugbread to Home & Garden (7 answers total)

There are a few things it could be; either something baked that side like a refracted reflection or exhaust from machinery, you have some kind of fungal pathogen that just isn't visible in the photos (sometimes the lesions are very small or the cankers originate back on the branches), or perhaps there is a root restriction under the surface of the soil, for example the belting material used to wrap the root ball could have been left on at planting and are girdling the trunk.
Try to remember if anything happened that caused heat, like an idling mower or pressure washer, etc. You can dig gently around the base a little to look for what should be a normal root flare, with the roots radiating away from the trunk in all directions. If you don't see that or see a specific place with anything strangling the tree, cut it. If it looks normal you should cut off a couple of branches that have portions that are both healthy and sick and take it to your local agricultural extension.
posted by Red Loop at 3:47 AM on August 19, 2016

Is this discoloration affecting other similar evergreens in your neighborhood?
posted by childofTethys at 4:19 AM on August 19, 2016

Response by poster: There has been no heat that I'm aware of, and location-wise I can't think of anything which would cause heat that reached that high up the tree. I'll check the roots and for discoloration in other neighborhood trees this weekend.
posted by Bugbread at 5:06 AM on August 19, 2016

It looks like there are some things in there- a chain, a vine. Make sure nothing is girdling branches or the trunk.
posted by release the hardwoods! at 6:42 AM on August 19, 2016

Junipers or whatever that is are messy and bits die. I would just cut out the bad parts and live with it.

And yeah, what's that chain doing?
posted by humboldt32 at 9:01 AM on August 19, 2016

Response by poster: Ah, the chain! (and rope!) A few years back the tree was on the verge of being blown over whenever typhoons rolled through, so there's a chain and a rope that are holding the tree to the fence in the foreground. Since it's been there for years it hadn't even occurred to me that it could be a factor, but given that trees grow, that makes total sense. Hopefully it's big enough now that it can withstand typhoon winds, so I'll take off the chain and rope. Thanks!

(and in case that's not the cause, I'll also double-check on the other evergreens in the neighborhood)
posted by Bugbread at 2:39 PM on August 19, 2016

Response by poster: I checked the chain, and it's still draped loosely. It's putting absolutely no pressure on the tree. The rope, on the other hand, was biting into the tree, so I cut it. However, the rope was about five feet from the ground. Could it have caused browning in the branches far below it, or would that just halve been coincidence?
posted by Bugbread at 7:14 PM on August 19, 2016