The old columnar blue spruce (Picea pungens ‘Fastigiata’) is ready to give up. In twenty years it has gone from nearly full sun to part shade, and the Bigleaf magnolia (Magnolia macrophylla) and a pink flowering ‘Satomi’ Chinese dogwood (Cornus kousa ‘Satomi’) have further crowded it. The lower limbs are nearly bare, and I figure…