When Jeffrey pine was first documented in the Shasta Valley of California in 1852, it was classified as a variety of ponderosa pine (Pinus ponderosa) because of its physical resemblance, but it turned out to be a species on its own.
There are two ways you can distinguish these two large trees from each other. First, the cones. The cones of the ponderosa pine have scale barbs pointing outwards. The cones of the Jeffrey pine, on the other hand, have their scale barbs pointing inward, so they are much more pleasant to the touch. Second, the bark. When you break off a piece of the deeply furrowed, flaky, cinnamon-colored bark of the Jeffrey pine during the growing season, it exudes an aromatic smell that is compared to lemon, vanilla, pineapple, violet, or butterscotch.
Jeffrey pine is a large tree that requires ample growing space, not only because of its height—one of the Jeffrey pines on the California Big Tree index is 184 feet high, with a trunk circumference of more than 24 feet and a crown spread of 69 feet—but also because of its extensive root system that allows it to adapt to poor soils.
Everything about Jeffrey pine is big. The bluish green or silver or gray green needles are seven to 11 inches long, and the egg-shaped to cylindrical cones six to nine inches long. The cones drop at maturity, but since Jeffrey pine is not suitable for a back yard and best grown in naturalized areas, littering should not be an issue.
Jeffrey pine can survive in harsh conditions, and in low and high altitudes. A life span of 150 years and beyond is not unusual. The most famous Jeffrey pine grew on Sentinel Dome in Yosemite Park in solid granite without soil. The seed was probably dropped there by a bird, and the tree rooted in a crack of the granite rock. Carleton Watkins photographed the Jeffrey pine in 1867, and Ansel Adams immortalized the tree in his famous photograph from 1940. When the tree died during a severe drought in 1976 and 1977 and finally fell over in 2003, it was supposedly more than 400 years old.
Jeffrey pine provides cover for birds, small mammals such as such as mice, chipmunks, and tree squirrels that also feed on the seeds. It is reported as highly deer-resistant.
Jeffrey pine is an important lumber tree.
|Botanical Name||Pinus jeffreyi|
|Common Name||Jeffrey pine|
|Plant Type||Evergreen tree|
|Mature Size||60 to 130 feet height, 20 to 30 feet width|
|Sun Exposure||Full sun to part shade|
|Soil Type||Loamy, sandy|
|Soil pH||5 to 7|
|Bloom Time||June to July|
|Native Area||Oregon, California, Baja, Mexico|
How to Grow Jeffrey Pine
The most important thing you need if you want to grow Jeffrey pine is space. The tree does well even in harsh conditions, but it is not suited for coastal areas.
Jeffrey pine needs six or more hours of direct sunlight. It will not grow in the shade.
It can grow in moist to dry soil, and in highly acidic to neutral soil pH. Any soil that provides excellent drainage, even gravel-like or rocky soil, is good.
The tree is highly drought-tolerant and does not require watering unless in periods of extended year-long drought.
Temperature and Humidity
Jeffrey pine adapts to cold weather with a short growing season. Great climate extremes as they occur in mountainous climates are not a problem. It prefers cool summers and does not do tolerate the hot and humid climate of coastal areas.
Like many native plants, Jeffrey pine does not require fertilizer. It can grow in nutritionally poor and even infertile soil.
Varieties of Jeffrey Pine
‘Joppi’ is a dwarf, globe-shaped variety of Jeffrey pine with similarly long needles as the original species.
Growing Jeffrey Pine in Containers
Jeffrey pine can be grown as a bonsai.
The most serious insect threat is the Jeffrey pine beetle (Dendroctonus jeffreyi). While beetle populations are often present, they cause the most damage and kill trees in periods of severe or extended drought. It’s usually only when the green crowns fade to yellow and reddish brown that the beetles are detected. The best way to prevent Jeffrey pine beetle attacks is to water the tree during severe and extended droughts in order to keep it healthy.
Other pests are aphids and beetle borers such as the California flathead borer.
Possible diseases include the fungi armillaria, phytophthora root rot, Western gall rust, and needle cast. Jeffrey pine can also be affected by mistletoe, a semiparasitic plant.