Yellow foliage on black pine - what's causing this?

(Jonas Dupuich) #1

I’ve seen this on a few of my pines and am not sure what’s causing it. The trees are otherwise healthy. My guess is that it’s related to too much water though I’m not sure why it affects some branches but not others. Any ideas?

About 4 years old

Close up

Different tree - only slightly yellow at this point

Another tree - the tips turned brown after a while

(Jeremiah Lee ) #2

Hmmm… very interesting I’ve never seen that before. I guess the tips turning brown could either be because of whatever is causing the yellow color, or it could be something else. I have a black pine with some brown tips on a few of the needles in certain areas only. Any idea what might cause brown tips on Black Pine in a certain area? I figured that it might be some type of pest.

(eric) #3

Looks kinda like a bad case of needle cast…but hard to tell. Do the buds on those branches grow after in the spring or do the branches just die? If they die then I’m guessing it’s needle cast. I have a root-over rock with a similar issue, but the yellowing is more generalized, with some branches being even more yellow like yours.

I’ve been meaning to do some research on the disease. There is apparently a known spore cycle that you can interrupt.

(Jonas Dupuich) #4

Thanks - the buds are actually in good shape. After reading about needle cast, I’m thinking more and more that it’s an abiotic problem. I’ll try to repot some of these this winter and see what I find in the soil.

(fabien m) #5

Hi jonas
i ve find on wikipedia .org a deasese called sphaeropsis blight
i thing its this affect your pine
north america est coast
top of tree gone yellow
blach pine …

(Jonas Dupuich) #6

Thanks Fabien - I’ve been reading a bit about Sphaeropsis sapinea and Diplodia pinea (Diplodia blight) as well as the somewhat similar Fusarium circunatum (a pitch canker). Each of these ends up killing the shoot and turning the foliage completely brown from what I’ve seen. My trees have yet to get to this stage. I plan to cut off the affected shoots as they aren’t necessary for the design of the tree - maybe I’ll send one to a lab.

(Jonas Dupuich) #7

Interesting - it could be a sport:

It’s similar to Burke’s variegated red pine too:

(Jonas Dupuich) #8

Just heard back from UC Davis Plant Disease Diagnostic Clinic: their assessment is that the yellowing is due to an abiotic condition. Possible triggers include:

  • too much fertilizer, specifically too much of some specific nutrient (though they didn’t suggest which)
  • root unhappiness due to poor drainage or too much water

In most cases the affected growth was near the top of the tree. The pathologist suggested that the conditions of the roots while these shoots were emerging help determine the condition of the foliage. The most vigorous shoots rely on healthy roots more than slowly growing shoots during growth spurts so they were good candidates for showing stress.

The tree in the photo is in dire need of repotting so it’s not surprising that it has the most yellow foliage.

As the clinic doesn’t think it’s a disease, they didn’t worry about the condition spreading to other trees. They suggested repotting the affected trees and experimenting with soil and fertilizer used going forward. We’ll see how it goes!