Arizona Pine Pinus ponderosa

The ponderosa pine is a large evergreen conifer that may grow to a height of 60 to 125 feet and 25 to 30 feet wide and has a pyramidal to conical habit. It is the dominant pine tree in the western United States and is used for timber. The needles are dark yellowish-green and occur n bundles of three. The cones are oval, pointed, prickly, and measure 3 to 6 inches long. The bark on young trees is dark brown to black. As the tree matures, the bark becomes orangish-brown, furrowed with large scaly plates. The bark, stems, and needles emit a resinous or turpentine scent when they are broken or crushed.

This tree is found in the mountain areas of British Columbia to Mexico and as far east as North Dakota and Texas. Three distinct regional varieties of this native tree often grow in pure stands.  In the Pacific coast region, the variety Ponderosa Pine or Pacific Ponderosa Pine has long needles, three in a bundle, and large cones.  Rocky Mountain Ponderosa Pine or Interior Ponderosa Pine has short needles, two in a bundle, and small cones.  In southwest Arizona, you can find Arizona Pine or Arizona Ponderosa Pine which has five slender needles in a bundle.

The genus name, Pinus, is Latin for pine.  The epithet, ponderosa, means heavy and refers to its wood. The tree was discovered by David Douglas, a Scottish botanical explorer in 1826. He named the tree for its ponderous or heavy wood.

The ponderosa pine prefers full sun, and moist, well-drained, deep soil but will grow in a wide range of conditions.  It will tolerate alkaline soils and is drought tolerant. It is fire-resistant due to its thick bark, and wind-resistant due to its deep tap root. This tree does not tolerate shade, flooding, or poorly-drained soils.

Its habit is narrow pyramidal in youth, with an irregular crown with age.  It has numerous short branches and drops its lower branches.  Old trees have no branches for more than 1/2 of their height. This evergreen is long-lived and may survive up to 600 years.

The ponderosa pine and the Jeffrey pine are very similar and obtain confused. The ponderosa pine has "prickly cones," and the Jeffrey pine has softer or more "gentle cones."

The ponderosa pine does best in its native habitat and is not recommended for planting outside of its native range. Due to its size, it would be best used in parks or large recreational areas.

Quick ID Hints:

• bark is dark brown in young trees, and orangish-brown, furrowed on mature trees
• needles are 5 to 10 inches long, rigid, and occur in bundles of three
• cones are oval, 3 to 6 inches long, 2 to 4 inches wide, prickly

Insect, Diseases, and Other Plant Problems:  This tree is susceptible to wind damage.  There is some susceptibility to root rot, blister rust, and needle blight. The Sequoia pitch moth can attack this tree by boring into the tree at injury sites or pruned areas and causing pitch and resin to escape. The tree is also susceptible to the bark beetle, adelgids, aphids, pine sawfly, and pine shoot moths. 

VIDEO created by Ryan Contreras for “Landscape Plant Materials I:  Deciduous Hardwoods and Conifers or Landscape Plant Materials II:  Spring Flowering Trees and Shrubs” a plant identification course offered by the Department of Horticulture at Oregon State University