The Monterey pine is a species of pine tree native to Mexico and the central coast of California. Though the sprawling tree is used in various ways (including as pulpwood) and is cultivated worldwide for lumber, it's actually considered rare and endangered in its preferred habitats.
Best planted in the early spring or fall, Monterey pine trees grow rapidly, adding upwards of 36 inches a year in height and reaching over 100 feet tall at maturity. In fact, they're the most rapidly growing pine trees in the world. Their needles are dark green and glossy but may appear to be more blue-green on older trees. The bark of the tree ranges from reddish-brown to black and features deep furrows and a rough texture. Monterey pine trees have ornamental value, too—in California, they are one of the most popular varieties of Christmas trees, thanks to their full and lush appearance. The tree is called Monterey pine in the U.S. since it is native to the Monterey Bay area near San Francisco in California. Still, since the Bay Area is not as well known outside of the U.S., it is best called by its botanical name: Pinus radiata.
|Botanical Name||Pinus radiata|
|Common Name||Monterey pine, insignis pine, radiata pine|
|Plant Type||Evergreen tree|
|Mature size||45–190 ft. tall, 15–30 ft. wide|
|Sun Exposure||Full sun, partial shade|
|Soil Type||Sandy, fast-draining|
|Soil pH||Neutral to acidic|
|Flower Color||Yellow, brown, cream|
|Hardiness Zones||7–10 (USDA)|
|Native Areas||North America|
How to Grow Monterey Pine
Monterey pine trees are easy to care for and quick to grow, making them useful as a landscape tree in many locations. In its young form, a Monterey pine tree has a nice pyramid shape, but as it grows taller, the canopy tends to flatten out. The wind may also transform the branches into various shapes, especially in coastal areas or on windy mountaintops. The trees also self-seed and may become invasive in some areas.
Monterey pine trees can live to be as old as 90 and serve as an important habitat and food resource for wildlife. Birds, rodents, and mammals all eat their needles, branches, bark, and seeds, as well as the many insects they attract.
Like the pond pine tree (Pinus serotina), the Monterey pine tree is serotinous, meaning the nuts need a heat source to be released. Once free from the tree, the nuts can be collected and ground into flour or eaten raw. They were a vital food source for early Western settlers—in very harsh winters, the inner bark of the tree could also serve as emergency food, and the tree's needles could be brewed into a tea that was rich in vitamin C. Pine resin (discharge from the tree) was also used well into the 20th century for various medicinal purposes, including treating burns and open wounds.
Monterey pine trees can grow in a range of full sun to partial shade locations. Their native habitats tend to be fairly sunny year-round, and because they grow so rapidly, it's unusual for them to remain fully shaded for very long. If planting a Monterey pine tree as a specimen in your landscape, choose a spot that gets at least six to eight hours of sunlight daily.
To reach their majestic height, Monterey pine trees need to be planted in fairly nutrient-rich soil with good drainage. The tree also grows best in soil that has a fair amount of sandstone nearby, hence its success growing in coastal areas, like dunes or bluffs. The soil surrounding the tree must be very deep in order to allow plenty of space for the roots; if the roots hit a rock, the tree can become unstable over time.
Regular watering is key to helping a young Monterey pine tree get established. Once the tree is established (after two to three months), it will be moderately drought tolerant and will need to be watered only during extended periods of dryness. If you notice that your tree is dropping an excessive amount of needles, that's a good indicator that the tree is in need of some water.
Temperature and Humidity
While Monterey pine trees can tolerate temperatures as low as 20 degrees Fahrenheit, they are best exposed to that type of weather briefly and will not flourish in areas that dip consistently below freezing. The trees are also humidity lovers and are happiest and healthiest when growing on coastal bluffs and soaking in the salty sea air.
Common Pests and Diseases
While Monterey pine trees don't have much to deal with in the way of pests, there are a few harsh diseases that they're especially susceptible to. One of the biggest issues for pine trees of all types (including the Monterey pine tree), is pitch canker, a fungal disease that causes swollen lesions to appear on the tree's trunk, branches, and roots. The lesions can prevent the tree from getting water, causing the needles to turn red, dry up, and eventually die off.
Other common diseases for the Monterey pine tree include root rot, needle blight, and tip blight. While not much can be done if an enormous tree comes down with an infection, you can trim off any diseased plants and keep the base of any specimen trees clear of debris or rotting foliage in order to prevent spread.