as i'm thinking about your question I'm imagining the space, and realizing that 3' x 8' is about the size of a sofa.I'm thinking you need bold visuals- rather than small fussy foliage-to play off the all-green back wall and to be seen across a distance from the walkway. I am thinking a small variegated weigela, which blooms a long time,along with a small deep purple presence- a patch of purple perilla or a mini dk. ppl.weigela or your ppl.heuchera idea.A 3-season patch of Yellow (that would also play nicely w/ the rozanne) could be provided by carex Bowles Golden or Hakonechloa or golden Tradescantia____ which would provide you some spiky form in the midst of mounded shapes.Also helpful for shape and color and height variety- would be the tall yellow flower spires of kirengeshoma and the ppl. foliage w/ white floral spires of cimicifiga black negligee. you might like 1 or 2 peonies next to your iris. best, mindy

The overhead sprinkler could be causing a lot of your issues. Are the needles getting wet from this system? You want to water at the base of the tree, preferably using a drip system of sorts. Needle moisture is the biggest problem I see so far. Watering at night is a very bad idea as well. In lawn care it is highly frowned upon because the water doesn't have a chance to dry off the surface of the grass quickly without the sun, moisture sits there all night, which again, encourages fungus. The same is true for trees. How are you checking moisture. How fast does you soil drain? I'm assuming slow, since it is clay. You will need to be especially careful with your watering program in clay soil. Spruces do not like wet feed, they like a quick drink and then near drying. Insert your finger to first knuckle to check for moisture. If dry water, if not, leave it alone. Dig a whole 1ft by 1ft. Fill it with water, let it drain. Then refill the hole and time how long it takes to drain. This will give you a visual understand of how long the water is sitting at the root level. How much Sun are the trees getting? This post was edited by SC77 on Thu, Jun 12, 14 at 14:11

I think the shade tolerance/sun requirements of these two species would be generally similar. I doubt that really specific information is available. For best growth/ best appearance, both will need full sun. But both can persist and maintain enough health to respond to release for some extended period of time in moderate shade. One problem making it difficult to get really specific information about small differences in shade tolerance, is that the relative shade tolerance of these species can be variable, depending on climate, soils, and specific strains of the Norway spruce involved. What seems true in one situatiion may not be true in another. Also, I think it would be difficult to find situations where the two species are both growing together in shaded sites so that good direct comparisons could be make--if fact, if there are any, I would think it would be very, very few. If you want a shade tolerant conifer, go with hemlock, if your area is free of wolly adelgids. Other wonderful shade tolerant trees are sugar maple and beech. I would go with those. Niether Norway spruce nor black hills spruce will provide really good long-term growth in shade, but both have considerable shade tolerance compared to many other kinds of trees. For a general comparison, both would have better shade tolerance than eastern white pine, which does have some reasonable shade tolerance when young. --Spruce

musicgalnd - just to clarify -- you probably don't want to water the 3yr transplants as heavily as I described above. by now they have mostly established and should not need that much water. a good soaking during dry spells is all. the replacements should get plenty of water this year. also, I don't trust the bucket with holes method. I just don't think it gets the water deep down into the rootball. it gets soaked up and dried off before it gets past the mulch/top soil. soak it good by hand, or poke a bunch of holes in a garden hose, rope it around the base of the trees, and let it run for 10-15 minutes. one other thing to check - I can't tell from the pics how deep they are planted. you want the root flare to be just visible at grade. if the trunk goes straight into the soil like a telephone pole it is planted too deep, and this will also hurt the tree. although that probably doesn't explain what you're seeing here.