Description
Populus – Aspen – Poplar – Cottonwood –
There are about 35 species of fast growing, short lived (60 years or so) of usually dioecious, mainly deciduous tree in this genus. They occur in woodland, valley bottoms, riverbanks, and swamp lands in North temperate regions. They are grown for their very rapid growth as specimen trees, and for their variable, alternate, ovate, triangular-ovate, diamond shaped leaves, often aromatic in bud and when unfolding. They have tiny flowers borne in catkins, generally 2-6″ long, mostly in late winter or spring, before the leaves, Male and female flowers are usually borne on separate trees, the females producing copious fluffy white seed (“cotton”). Most poplars are useful as windbreaks, P, alba and P. x canescens will thrive in coastal sites. The vigorous root systems may damage drains and foundation, so avoid growing poplars within a 100′ feet of a building.
Tolerant of any, except constantly waterlogged soil, although best in deep, fertile, moist, but well drained soil in full sun.
Prone to borers, leaf miners, caterpillars, scale insects, leaf hoppers, canker, butt rot, crown gall, dieback, root rot, leaf blister, white rot, rust, and powdery mildew.
P. trichocarpa – ‘Black Cottonwood – Western Balsam Poplar – This fast growing, conical deciduous tree from Western North America grows at least 80-100′ feet tall and 30′ feet wide. It has furrowed grayish bark and brittle branches. It produces leathery, shallowly toothed, ovate to egg shape, glossy leaves, to 10″ long, dark green above, white beneath, turning yellow in autumn, and strongly balsam scented when young. In mid spring it bears red male catkins, 3″ long, or green females, to 6″ long.
Zones 4-9
