New needles – midsummer to Oct., older needles- May to Oct (worse in Sept & Oct)

Usually early in growing season, June - July – as new growth develops (occasionally into early fall).

5 weeks to 6 months

One month to 6 months depending on pine and age of pine (young plants show symptoms quickly as do Scots pine and developing needles).

Water soaked lesions that become tan to light brown spots – needles may break off or fold at the infection site. Young trees more than older trees and more often on the lower branches.

Brown spots with yellow halos - other coloring of spots possible. Eventually needles turn all brown. New shoots & needles may die by winter. If shoots stay alive then older needle die earlier in succeeding years. Needles may or may not fall off by late fall. Occurs more often on lower branches.

Throughout the year

Summer (June – August)

Austrian & Ponderosa -mostly, lodgepole, mugo, Japanese red –often, Scots and red usually resistant

Ponderosa, Scots & red - most, Jack, mugo, pitch, eastern & western white & black -sometimes

Several days of cool and wet or cloudy days. Growing the trees outside their native habitat makes them more susceptible.

Warm/hot and wet and may take 3 years to reach epidemic conditions

Good air circulation, plant native species of pine.

Grow resistant varieties, plant disease-free trees, allow for good air circulation, do not prune when trees are wet.

In lesions of infected needles

On dead needles

As new growth emerges some research indicates fungus may be in plant tissue the previous year but does not cause infection till following year.

3 – 4 days (in warm weather) to several weeks

Bleeding at base of branch tip & yellow- browning of foliage, internally the tissue is reddish brown and resinous (can be a severe canker problem on branches and trunk producing large globs of oozing sap over the infected tissue, xylem may turn gray to black in canker area – tree can be killed).

Late spring to fall

Austrian, Ponderosa, Scots– most. Red, mugo, & other 2 & 3 needle pines -sometimes

Temperatures between 55 and 100° F. & 12 hours of wet weather during bud break and candle growth for tip blight. Planting pines outside the native range and habitat.

Plant less susceptible pines. Use only native pines.

Infected needles on tree and ground, infected cones (green or brown), shoots, needle sheaths and canker areas