I'm not sure I'd agree with Ken's assessment :-) Standard American arborvitae often do display interior browning - it is simply a manifestation of the interior foliage being shaded out by exterior growth (plus the natural lifespan of healthy foliage) and is entirely common. However, the threadleaf arborvitae has a very different growth habit that pretty much excludes significant shading of the interior growth, at least to the same extent as the denser, more upright forms. Plus, the plant in the photos is displaying some discoloration on more exterior growth as well, which leads me to believe that there may be some moisture issues involved, most likely a drier than optimum rootball. Make sure drainage is adequate and the plant is sufficiently hydrated, especially as it enters winter. And not planted too deeply. Fertilizer is not indicated at this time but you may want to consider an all purpose fertilizer in spring as new growth commences. It is unreasonable to assume that any plant never needs fertilizing in a cultivated situation - that is entirely dependent on existing soil conditions, not the the plant itself - although for well-established woody plants, the need for supplemental ferts is typically quite small......that's well-established woody plants.......:-) btw, a conifer can certainly be considered a shrub. That term - shrub - only refers to a habit or manner of growth, not a botanical classification, and can apply to conifers as well as any other woody plant.

Easy answer...ask me in the spring if they are dead or not. Complicated...may not be fully answered until the spring. If your fall has been dry, water, perhaps add a layer of mulch (leaves or straw). Other than weather (temperature), one the most important factors influencing the hardiness of plants is availability of water going into winter. Given the fact that these are older, established plants, it's probably nothing to get concerned about. Most likely, it's just a cyclical thing that unless you have massive amounts of climatology data, a fully equipped lab, and more spare time than is safe to admit (especially if you are married), it just ain't worth trying to comprehend. If you really want to do something, water and mulch, assuming you have had a dry fall. If you've had a moist fall, more water is not needed. If it were me, I'd wait. They'll make it or not, and most likely will anyway, no matter what you do. Thankfully, plants are a) tough b) adaptable and c) forgiving. Whatever you decide, best of luck.

Thank you all for the replies and thoughts. When I removed the burlap, the clayey root ball seemed very moist, so I believe it was adequately moistened. I have since placed a soaker hose in my garden bed (under 2-3" of mulch) with a full loop around the base of the tree, so we'll see what happens with soaking for a longer period of time rather than 5-10 minutes of direct hose spray. I also want to note that I planted a new rhododendron immediately adjacent to the emerald green about 2 weeks ago, and I just noticed today that the rhody appears to have a disease, which looks an awful lot to me like phytophthora ramorum. I think I have heard that arborvitaes are also susceptible to this disease. Do you think there might be a connection between the rhody and the arborvitae? I am probably going to pull that rhody out and bring it back to the nursery where I got it, as it was only a few weeks ago. I posted photos of the browning arborvitae foliage, and of the rhododendron.

Sorry for the typo.