(E = evergreen)
Spruce is particularly suited to cold northerly regions or hill districts, where it may be planted as late as May or early June, but it is generally planted either in October or April. Although usually grown up to 50 ft. as a screen, spruce also makes an effective hedge up to 15 ft., or at most 20 ft. tall.
For a hedge, put in transplanted seedlings 2 ft. apart when they are 9 to 12 in. high. Mulch with leaf mould for the first two or three years. Between June and December, prune out any branches that grow out of proportion to the rest, and until the shape is established, maintain bushy growth by tipping back the leading shoots in autumn.
When planting spruce as a screen, put in the young plan
ts 6 to 8 ft. apart when they are 3 ft. tall. Remove alternate trees when the branches overlap.
Picea abies (Norway or common spruce), an excellent background tree in cool, moist conditions inland. Dense, glossy, dark green foliage.
P.glauca (syn. P. alba) (white spruce), has very glaucous blue foliage, which gives it a grey, frosted appearance.
P. pungens, glaucous green leaves. This species is particularly susceptible to the green spruce aphid, and has two striking varieties,
P. p. argentea, silver-green.
P.p. Glauca, blue.