Red Spruce

Size, growth and what to expect

Red spruce grows at a medium pace, about a foot and a half a year in our growth estimator. On a good site it reaches about 23 feet in 20 years and 62 feet in 60. It matures at 60 to 75 feet with a narrow crown 10 to 18 feet wide. Its maximum age is about 400 years.

Pollen is shed in late April and May, and the cones ripen from mid-September to mid-October. The reddish brown cones are 1.25 to 2 inches long and fall soon after they ripen. Its seed makes up a quarter to half of the white-winged crossbill's diet, and spruce grouse eat its buds and needles.

It grows wild from the Maritime Provinces and Quebec south to northern New Jersey, and along the Appalachians to North Carolina and Tennessee. In the southern mountains it grows above about 4,500 feet, and above 6,200 feet Fraser fir outnumbers it.

How to grow Red Spruce

Red spruce needs a cool, moist climate and dislikes summer heat. Give it full sun or light shade and an acid soil that stays moist but drains well. It takes thin, rocky soil, but on poorly drained ground its roots lack air and it grows poorly. Its roots are shallow, so give it shelter from strong wind. Plant it 20 feet from a wall, and set trees 12 feet apart for a screen. Keep it more than 50 feet from overhead wires.

Saplings ship bare-root or potted. Plant in early spring or fall, in a hole wider than the roots and no deeper. Set the root flare at the soil line, put the native soil back in, and keep the mulch clear of the trunk. Seed needs no chilling. Sow it in spring, barely covered, in a bed kept moist and lightly shaded. Seedlings come up in late spring and grow slowly at first.

Water weekly through the first two summers and in dry spells after that, since drought is a major killer of young spruce. Keep a mulch of leaves or bark over the shallow roots. Deer find it unpalatable. It needs no pruning beyond dead wood.

Each tree carries both male and female cones, and the wind carries the pollen. Much of the seed a lone tree sets with its own pollen is empty, so trees in a group bear better. It can bear cones at 15 to 20 years once its crown reaches full light, and good seed crops come every 3 to 8 years. Spruce budworm is its worst insect pest, though it suffers less than balsam fir. The eastern spruce beetle and sawflies damage mature trees. It has few diseases.