I have about 9 Green Velvet Boxwoods planted in groups along the north side of my house. They were planted May of 2018...so been in the ground about 2 1/2 years. They were fairly small specimens when planted. Zone 6, central Indiana. Full sun throughout the height of the summer, this time of year they get a little less as the house starts shading them mid to late afternoon. They've grown fine, 2-3 inches of new growth each spring...and I've never had any dead in them. About half them however, maintain a somewhat paler, yellowed, almost bronze hue from mid summer on. The new growth is always the normal light green...but it doesn't darken to the expected dark green color. In the pics you can see the difference between some a mere 3 feet from each other.

Properly mulched and I never use any fertilizers in my beds. They don't receive supplemental water...as rainfall keeps this bed moist all summer. Nothing indicates blight...no dead, no falling leaves, and no blisters on the leaves. I had 2 thoughts...maybe I keep the bed mulched too heavy for boxwoods...do they require a lighter layer of mulch? Secondly, now that's they are settled in, maybe I could have planted them a couple inches higher? The root flare is slightly higher than the soil line...but I guess I could have raised them a little and planted them on more of a mound. Drainage is ok, but probably not excellent...soil is a little clayish.

Any thoughts? Pale and yellowed leaves always makes me believe too moist. Here in Indiana we usually get our first hard freeze early to mid November...is it too late to lift them up, and backfill underneath them to try to help them drain better next spring? Or maybe they are just duds?