The ponderosa pine tree (Pinus ponderosa) is a large evergreen that lives 300 to 600 years. Native to mountain and plateau regions of the United States, the ponderosa pine develops a taproot early in life that enables the tree to survive stressful conditions such as extended drought. The tree is naturally a slow grower.
The ponderosa pine typically reaches 100 to 164 feet in height with a trunk that is 3 to 4 feet in diameter. Especially old specimens have been measured at more than 200 feet tall with trunks 7 feet in diameter.
The ponderosa pine has a straight trunk, the lower half of which is branchless. The tree's crown has a rounded cone shape, and the scaly bark is orange-brown. The ponderosa pine's pointy, serrated needles are 5 to 10 inches long and usually appear in groups of 3. Flowering occurs from April to June, and pineapple-shaped, prickly male and female cones develop on the tree. The cones mature and produce seeds in August and September of the following year. The bark on young ponderosa pines is black and scaly. As the trees mature, the bark thickens to as much as 4 inches and develops into large, flat plates separated by deep fissures. Old trees have yellow bark, which is why the tree is commonly called yellow pine. The bark of mature trees smells like vanilla or butterscotch, and the wood of old ponderosa trees is prized for its strength, light weight and fine grain. The wood is commonly used for lumber, railroad ties and millwork.
Ponderosa pines grow in USDA hardiness zones 3 through 7. The tree is found throughout the states of Washington and Oregon and portions of Texas, Nebraska, Oklahoma, South Dakota and North Dakota. Common in mountain and plateau areas at elevations of 5,700 to 8,900 feet, it grows in mixed conifer forests, as well as in groves on its own.
Ponderosa pines grow in a wide variety of soil types, from sandy to clay, and it's even found thriving on rocks with roots growing in cracks and crevices. The tree does best in well-draining soil that has a pH of 6.0 to 7.0. Established ponderosa pines survive in hot, dry locations with little irrigation, although they grow best when the average annual rainfall is 12 to 24 inches. The tree also survives freezing temperatures.
Ponderosa pines grow from seeds that come from the cones. Once planted, the seeds germinate in about 15 days when the temperature is around 68 degrees Fahrenheit.