Wouldn't be at all surprised if it was cold damage. Pinus wallichiana is marginal in zone 7, not zone 4. That it is even alive at all rather suggests it is the hybrid P. à schwerinii (P. wallichiana à P. strobus), but even that is probably close to its limits in zone 4.

Resin

i lost 5 wally's in zone 5 ...

expensive lesson learned ...

get every drop of enjoyment from it.. while it is there

ken

Green bark is from chlorophyll in the cortex tissue. This is replaced by bark forming underneath, a process which kills the cortex.

Pinetree -- Are you saying this is a normal process as the tree ages, and not due to environmental damage?

Resin -- This tree was obtained from a St Paul area nursery that special ordered a few P. w's for a doctor in town, who was in some sort of "collector" competition with a colleague. I mentioned the prospect of it being a hybrid (they have Pinus à schwerinii at the U of Minnesota arb) and he flatly rejected the notion. This doesn't mean its not so, just that the nursery manager was familiar with the hybrid and said he specifically sought out the species. I'm hoping it stays around long enough to see it produce cones so I (ah, more likely you) can make a positive ID. Its in a very protected location, but the jump from z7 to z4 does seem just a bit unrealistic.

BTW, what is the earliest age you'd expect it to produce cones? I've got a seedling P. sylvestris that is seven years old and produced cones for the first time this year, which seemed pretty young compared to the native pines growing here.

Bob

Hi Bob,

If true P. wallichiana, I'll be extremely surprised if it lives long enough to have cones. But generally, it tends to bear fairly young though not as young as Scots Pine, more like say 12-15 years old.

What Pinetree says is true of the normal aging process, but that red-brown shows complete tissue death, and is happening much too soon; Pinus wallichiana bark typically stays smooth green-grey for at least 5-10 years. Scrape it there, and I think you'll not find any green under the bark, just dead brown right down to the wood. If the brown goes all round the stem, it is girdled, and the branches living on borrowed time.

Resin

Well, transitions like going from cortex to bark are not on a timetable, as far as I know, but I'm not a grower and have no experience with this species. Freezing damage that discolors the stem but allows buds to stay healthy enough to form long vigorous shoots is also something I haven't experienced. So I'll go with normal cortical breakdown and no freezing damage, and wait until the evidence for both rolls in.

I'll keep you posted. Nothing personal, Resin, but I'm pulling for Ron on this one. :)

Is there red sap I'm seeing and if so is this from the peeling of the bark because of the possibility of cambial damage for whatever is a reason...?

Dax