Pinus strobus (Eastern White Pine, Northern White Pine, Weymouth Pine, Soft Pine)

Pinus strobus, frequently known as the Eastern White Pine, is a fascinating tree (well, at least to me). This was the first conifer that I ever took notice of and chose to study. The first pine needles and conifer cones I collected were from an Eastern White Pine, which I investigated as the unusual growth formation perplexed me. These types of trees grow unusual horizontal branches with very soft pine needles in bundles of five. The cones are darker brown and longer than “typical” pine cones. When older, these trees have buttressed bases, and their growth slows down from rather quick to moderate. These trees don’t seem too special when young, but older specimens can be truly mesmerizing.

Pinus strobus (Eastern White Pine, Northern White Pine, Weymouth Pine, Soft Pine)
Family: Pinaceae
Subspecies: ‘Pendula’, ‘Chiapensis’, ‘Strobus’, ‘Glauca’
Native: eastern United States
Hardiness Zones: 3-8
Height: to usually 24 meters, “champion tree” at 68m
Diameter: to 12m in cultivation
Root System:  usually 1 meter deep
Growth Rate: begins moderately quick, slows with age
Age: maturity between 100-200 years old, some to 400 years old.
Deciduous: no
Monoecious/dioecious: monoecious

Tolerates: a wide range of soils, deer, and rabbits
Problems (major): intolerant of urban pollution, white pine blister rust (bark disease, tends to be fatal)
Problems (minor): white pine weevils attack buds, possibly warping shape
Poisonous: no

Soil requirements: well-drained, slightly acidic, fertile soils preferred; tolerant of most soil types
Air Requirements: non-polluted air required
Watering requirement: medium
Sun requirement: full sun required with age

Needles: soft, to 13cm long, in bundles of five (only native pine to have 5 needles per peg)
Cones (male): inconspicuous, small, green
Cones (female): to 20 cm long, brown, thin scales, curving to be slightly sickle-shaped
Seeds require stratification: yes

Notable characteristics:
This pine grows in a very atypical fashion with horizontal branching. Native to the eastern United States, this tree is one of the tallest pines in North America. This is also the only native eastern pine to have bundles grow in bundles of five. Their cones are unique in the sense that they are very elongated and easily distinguishable from other conifer cones. It grows a buttressed base as it grows older to increase the tree’s sturdiness. The needles are unusually soft and aren’t prickly in the slightest. While it isn’t very tolerant of pollution, they grow very well in the suburbs and along expressways where factories aren’t present. They offer excellent shade in the summer due to their unusual growth formation.

Uses:
This was arguably the most important timber tree in the 1800’s and 1900’s. Unfortunately, this led to a great many being cleared. The wood is prized for being easy to use and fairly rot resistant. Once used as ship masts, these are now used for crates, boxes, carving, boat-building, and construction lumber. Planted as a shade or ornamental trees in places where air quality permits.

Sources used:

EWP_1

A fairly young specimen with mostly horizontal branching

pinus_strobus_expressway_1

Older trees along the expressway in a large group

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The bark/trunk

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Several immature, green, resinous, nearly terminal cones in early summer

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A close-up of a twig with needles, 5 per point

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Cone primordia thawing from a night of freezing rain and ice

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Young adult form

All of the images provided were taken by me. They may be used for educational/informational purposes only, provided that this article/online journal is appropriately cited first.

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