I find some bronze in too much sun and heat. However, they do need some sun, morning or evenings, to keep the brightest colors.

That said, Fireglow stays gorgeous. Red Dragon, Trompenburg, Dissectum Nigra, Nuresagi, Garnet, Red Crusader, Lozita, Crimson Queen, Red Pygmy, Red Emperor, Chantilly Lace, Burgundy Lace, Octopus, Toyama Nishiki, Crimson Carole, and Okagami, come to mind at the moment.

I've got a lot more reds that remain red. Shade is factor, but I've not experienced what you've been told. They do darken or brighten as the season goes by. As a matter of fact, though, I have almost no shade. Tornadoes took down my only 2 shade trees. What I have left pretty much needs full sun.

This post was edited by CEFreeman on Sat, May 3, 14 at 14:57

1. Yes, this is true. It is also true that some red leaved cultivars will 'bronze' out in too much sun. Ideally, you will want to site just about any Japanese maple with morning sun/afternoon shade or filtered or dapped all day shade. All red leaved JM's will develop the best leaf color if they get at least a few hours of direct sunlight.

2. I would trust ONLY plants from known reputable growers and retailers of Japanese maples. And even then, there can be tagging or ID errors. Box stores buy in bulk from whatever vendor offers them the best deals. These are not always the most scrupulous of growers and have been known to sell seedling JM's by cultivar names - a HUGE no-no! Box stores also tend to have only the most common cultivars whereas independent garden centers that specialize in JM's will offer a very wide and high quality selection. It is a bit of a case of you get what you pay for :-))

3. No. Trunk color has little to nothing to do with foliage color.

btw, 'Tamukeyama' IS a cultivar. There is just one with that name and ALL Tamukeyama's should look the same.

Thank you both for your responses. CEFreeman- I see that bronzing with my neighbor's JM that is in full sun most of the day. I am surprised it survives because we have ~25% 100F+ days during the summer. I have a bright green JM in my mostly shady back yard. I had it in a place that got more sun, and it was starting to get scorched in the summer, even with deep watering. I moved it to more shade, and now it is very happy.
Gardengal48- thanks for your answers. I totally agree about "you get what you pay for". But I I think am going to take the risk with the Crimson Queen at Lowes because it is of gorgeous condition and form (just went and looked again today, and picked out two large ones that I will pick up Friday). The red is very vibrant as well, not the "purple" that I tend to see at big box stores. I realize I am taking a risk, and worst case, I may have to gift them to a friend if they green out. Also, I am having adjacent trees trimmed so that there is more dappled sun in those areas. Keeping fingers crossed!

I admit to being confused about red bark on a Crimson Queen. The only red bark I've seen is on Coarl Bark and their hybrids.

Post some pictures!