It was suggested "Exact diagnosis can be made by taking a sample to your local extension office but if it is Phytophthora (or another root invading fungus), there is little you can do now." If such a sample is brought to the Extension Service office, please call ahead so that the Master Gardeners have time to locate information as to how to sample the soil & the affected root tips. Also know that a fee is charged, the precise amount depending upon the test to be done -- fees for the OSU Plant Disease Clinic begin at $40.00. Beyond that, I doubt this will be an easy diagnosis. I'd consider multiple factors potentially contributing to the problem: 1. Because OP said s/he "paid quite a bit of money" I suspect it is a sizable specimen. If so, post-plant irrigation is a critical factor in survival. All transplants should go into evenly moist soil, then the rootball should be supplied with more water than the surrounding area during the following months. Failures of recent transplants typically are due to water -- either too much or too little. 2. The sudden very cold weather in December, without snow cover, damaged & even killed many plants hereabouts, including those which survived 10 years or more. 3. The tree is a recent transplant. As such it is more likely to be damaged by cold than an established tree of the same kind. 4. Dormant roots are less susceptible to water damage than are actively growing roots. 5. In general -- and yes, exceptions exist -- root rot results in entire tree failure. 6. It's nigh to impossible to diagnose root rot by looking at dead branches and/or browning leaves. 7. And perhaps most critical, multiple nearby specimen maples are in potential jeopardy if the problem is indeed soil-borne, such as Phytophthora root rot or verticillium wilt. So, I suggest pinkswine consider having a certified arborist or two come for an on-site evaluation. To locate a certified arborist, look in the Yellow Pages under the heading of Trees or something similar. Ads for companies with a certified aroborist will either have a statement or small rectangular logo stating such.

I say pot some up and sell away....those who are offended by that need not come over to buy. I personally would be delighted to buy potted plants/seedlings from one of my neighbors and help them out with a little extra spending money and get myself a nice maple seedling in the process. Much nicer than driving to the big bix center. I bet in future I would be more far more likely to remember the tree I bought from a friendly neighbor than something I bought at the store and like it all the better for that. Once Spring hits, my neighbors' kids sometimes set up a little flower stand (basically a card table) with some cut flowers to people going to the nearby cemetery (we live near the entrance). They did not plant the flowers, the previous owners of that house were avid gardeners, yet I have seen many touching interactions with the kids and the people who stop to buy them for their departed loved ones....it makes the flowers all the more meaningful than something bought at the store and seems to really brighten up the visitors who are often melancholy. It's also a nice rite of Spring for me to see and I will be sorry when the kids will all too soon grow up and no longer want to sell flowers from their driveway (and yes, I do buy their cut flowers from them when they are out there, though I have plenty of my own...we both get something out of the bargain!)

I obviously don't live in Toronto so can't comment about the suitability of this tree for that area. But I will let you know that colored bark Japanese maples are extremely prone to bacterial blight, Psuedomonas syringae. And this pathogen is encouraged by winter cold damage and cold, wet springs. Even in my very mild winter area, pseudomonas is common on these selections because of spring weather. And it can be fatal. I would site the tree so that it receives maximum winter wind protection and in whatever microclimate you can manage........any "L" formed by the house or other structure, reflected heat from a south facing wall or paved area or in the shelter of other larger growing (and preferably evergreen) trees or shrubs.

Ivan, I think it is taking it down a few notches to introduce the alternating pattern of plantings. The look seems unsophisticated to me. (Not to say that an alternating scheme is always impossible. Sometimes, pulling it off relies on proper scale and usually involves radically different plant types.) I think you'd be much better off to use a triad grouping of coral bark and a line or single of the other. Too, I think you should be thinking of the CBM in a tree form, not in a shrub form as the above computer image appears. Ultimately, it's canopy is going to be above the fence rather than in front of it.