Pruning may be necessary to maintain its desirable growth habit. Mugo pine is susceptible to pine needle scale. Spruces can be recognized by the persistent leaf bases that remain on the twigs after the needles have fallen. Spruces are native to cool climates and therefore are poorly adapted for growing in most of Missouri. They should be planted only on well-drained soils.
Young trees are attractive with their dense foliage and symmetrical growth habit.
The four spruces described in the following section are the ones most commonly available in the nursery trade. Norway spruce is one of the fastest growing of all the spruces. As the tree grows older, the side branches become horizontal with a slight upturn at the tip. Secondary branches hang downward from the main branches, giving the tree a graceful appearance. Black Hills spruce, a slow-growing, compact variety, is one of the hardiest of the spruces.