Pines species that are commonly grown in our area include the following:
White pine: the beautiful, large, open-crowned state tree. Where they are happy in our area, they require no special attention; where they are yellow and unthrifty, it is usually due to site conditions -- heavy clay, high pH, poor drainage -- things are are difficult or impossible to correct.
Red pine: native to northern Michigan, but not commonly planted here. Sometimes they perform adequately, but more commonly they are intolerant of the heavy soils and muggy summers.
Scotch pine: introduced from Europe, it is noted for its bright orange bark.
In our area this species is doomed by the pine wilt nematode (see sidebox
right), over which there is no control. Once infected, this tree dries out
and dies rapidly.
Austrian pine: the most commonly planted species because of its tolerance
of heavy soils. If you get more than 20 years of good growth out of a specimen,
you are beating the odds. See additional information below.
Mugo pine: this plant is commonly used a shrub, although cultivars can grow quite tall. It is susceptible to Diplodia tip blight (see below) if grown in the shade. Sometimes homeowneres are freaked out by large populations of gregarious sawflies ('see photos below') that can quickly strip a plant of old needles. Pine needle scale can also be a problem.
Diplodia Tip Bight: this fungus (also known as Sphaeropsis) is the most common problem affecting Austrian pines. The new shoots turn brown before the needles have fully expanded. Preventative fungicide sprays need to be applied annually. Improvement should be noticeable within a couple seasons, although some specimens are recalcitrant. Trimmng will improve appearance but not reduce disease inoculum. Damage by the European pine shoot borer can looks similar, but breaking the shoots will reveal a mass of insect frass (the technical term for 'insect poop').
