Life Cycle of the Lodgepole Pine

Climate

• You can grow lodgepole pines in U.S. Department of Agriculture plant hardiness zones 2 through 8, but knowing their ability to survive winter low temperatures weather is not enough to understanding how lodgepole pines grow and reproduce. They are adapted to thrive in thick stands on mountain slopes and are typically found at elevations above 5,000. Forest fires are crucial to their reproduction.

Cycle of Cones

• The cones of lodgepole pines are serotinuous, meaning they have evolved for delayed opening. Lodgepole pines have separate female and male cones. Large, orange-red male cones grow in clusters. A resin seals the scales of the cones of the egg-shaped, tan female cones that are about 1-1/2 inch long. Lodgepole pine cones remain on the tree for 10 to 20 years, waiting for a temperature between 113 to 140 degrees Fahrenheit, necessary to melt the resin and free the seeds. Forest fires are necessary to provide the heat.

Needle Cycle

• The yellow-green to dark green needles of lodgepole pines are short, typically from 1-1/2 to 3 inches long and come in pairs. The leaves are typically twisted, giving the tree its species name contorta. They remain on a tree for six to eight years.

Maturation

• In western mountains forest fires needed for lodgepole pine regeneration are often caused by mass infestations of the western pine bark beetle. Dry windy, conditions can cause forest fires to sweep through stands of lodgepole pines leaving fertile seeds behind. Lodgepole pines begin reproducing when they are 5 to 10 years old. They typically live in dense stands and can live to be 200 years old.