Balsam Fir

Size, growth and what to expect

Balsam fir grows slowly, about a foot a year in our growth estimator. It matures at 40 to 75 feet with a narrow crown 15 to 25 feet wide. It is short-lived for a conifer, with a maximum age of about 200 years, though the oldest tree dated by its rings reached 245. It fails in hot, humid summers and seldom does well outside northern New England, the Great Lakes states and Canada.

Cones can appear on trees as young as 15, and good seed crops come every 2 to 4 years. Pollen is shed in May and June. The upright cones, 2 to 4 inches long and purple when young, ripen from late August to October. Spruce and ruffed grouse eat the needles and buds, and red squirrels eat the seed.

It grows wild from Labrador and Newfoundland west to Alberta, and in the United States from Minnesota and northeastern Iowa east through Wisconsin, Michigan and New York to New England. It reaches south to central Pennsylvania, with scattered stands high in the mountains of Virginia and West Virginia.

How to grow Balsam Fir

Balsam fir wants a cool, moist site and does best in full sun, though it grows in shade. It needs a slightly acid soil that stays moist, and it takes wet ground but grows poorly in heavy clay and on dry, exposed sites. Its roots are shallow, so shelter it from strong wind. Plant it 15 feet from a wall, and set trees 15 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. Sow the seed outdoors in fall without any treatment, and seedlings come up in late spring. For a spring sowing, keep it damp in the refrigerator for one to two months first. Expect only a quarter to half of the seeds to sprout.

Water weekly through the first two summers and in every dry spell after that, since it succeeds as a screen only where its need for moisture is met. Keep a mulch of leaves or wood chips over the shallow roots. Moose, hares and deer browse young trees, which slows them but seldom kills them, so cage saplings where browsers are many. It needs no pruning beyond dead wood.

Each tree carries both male and female cones, and the wind carries the pollen. A lone fir can bear normal-looking cones whose seeds are empty, so trees in a group bear better. The spruce budworm, which prefers fir to spruce, is its worst pest, and trees usually die after 3 to 5 years of steady defoliation. The balsam woolly adelgid, an introduced insect, can kill a tree within 3 years of attacking its trunk. The elongate hemlock scale also feeds on fir, yellowing the needles and thinning the crown. Rot can begin at about 40 years and infects more than half of trees by 70, weakening them against wind.