Tsuga mertensiana Mountain Hemlock Small younger tree near 4000 feet elevation - Rogue River National Forest at Blue Ledge Mine. Landscape use in Oregon near 200 feet elevation.
I've noticed a tendency for some wild collected plants to become more blue after living in the lowlands for awhile. Perhaps warmer, drier lowland conditions promote this.
In Oregon, quite a few up on the mountains that grew naturally, seem a bit on the greenish or yellowish side. It may be that the soil and conditions are a bit harsh on the mountains. Good possiblility of less nutrients. The growing season is definitely shorter on the mountains. Next summer I plan to drive up to Mt. Hood for a day or two. I'll pay closer attention to see what sort of spots the more blue color ones are growing in.
Although it varies of course the dominant color is green in the mountains here, whereas in lowland cultivation blue dominates. What I have observed to account for this is individual specimens coming from the mountains mostly green and then becoming predominantly blue after growing down here for awhile.
I'd suspect that may be because the harsh environment in the mountains (perhaps particularly ice blasting in gales) wears off the blue wax on the needles.
Have any of you noticed a disease attacking the Mt Hemlocks in your areas? We are seeing tip die back, twisting of the last years growth and defoliation, in both wild sites and planted ones?
Didn't pay close attention last summer, but remember a few years ago where some tips browned following a flash of hot sunny weather during late spring. Not sure if there was any twisting, but maybe a teeny bit of curving.
