Tamarack

Size, growth and what to expect

Tamarack grows fast, about 2.75 feet a year in our growth estimator. A good plantation in Ontario averaged 49 feet at 25 years, though growth slows after 40 to 50 years. It matures at 50 to 75 feet with a narrow, open crown 15 to 30 feet wide. Its maximum age is generally 150 to 180 years.

Pollen is shed in late April and early May as the new needles appear, and the cones ripen in August and September. The upright cones are half to three quarters of an inch long, rosy red when young and brown when ripe. The needles start to yellow in early September, reach full color in early October and drop by mid-October. Crossbills and pine siskins eat the seed.

It has one of the widest ranges of any North American conifer, from Newfoundland and Labrador west to Alaska and south to southern Minnesota, northern Ohio and northern New Jersey. Isolated stands grow in the mountains of West Virginia and Maryland. It grows mostly in bogs and swamps, and also on moist ground along streams and lakes.

How to grow Tamarack

Tamarack needs full sun, and it will not grow in the shade of other trees. It wants soil that stays moist or wet, and it does well on acid peat and on clay. It does poorly in summer heat and in city pollution. Dry, shallow or chalky soil does not suit it. Its roots are shallow, and strong wind can uproot trees on wet ground. Plant it 20 feet from a wall, and set trees 20 feet apart for a grove. Keep it more than 50 feet from overhead wires.

Saplings ship bare-root or potted. Plant it while it is dormant, in early spring or in fall after the needles drop, 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 seed outdoors in fall a quarter inch deep. For a spring sowing, keep it damp in the refrigerator for 20 to 60 days first. Germination is often erratic and poor, even in a greenhouse.

Water weekly through the first two summers unless the ground stays wet, since young trees stand neither drought nor flooding well. Keep grass and weeds away for the first two years. Deer and moose seldom browse it, but hares and porcupines damage young trees. Prune, if needed, in midsummer.

Each tree carries both male and female cones, and the wind carries the pollen. Its own pollen yields mostly empty seed, so a lone tree bears far less sound seed than trees in a group. Trees can bear seed at 12 to 15 years, and good crops come every 3 to 6 years. The larch sawfly and the larch casebearer strip the needles, and years of heavy attack can kill a tree. Although it grows in bogs, a lasting rise in the water level can kill it.