Black Hills Spruce
The symptoms you described and are in your photo can be from either over or under watering. I would remove some of the stone under and round the tree, then check the moisture of the soil ( is dry or wet ). Check below your tree, dig down 9 inches or so several areas around the soil ball. A soil probe works well for this. Your soil should be moist, if it is soaking wet, you’re over-watering. If your soil crumbles or feels dry then you are under-watering the tree. Sometimes in clay soils you can create a "bowl" effect that causes the water not to drain quickly and hold moisture in the root zone.