Pinus strobus (White Pine)

Michael's Opinion

Pinus strobus is the provincial tree of Ontario. Tom Thompson of the Group of Seven often painted this majestic tree and made it famous for its wind blown appearance.

Botanical Information

FamilyPinaceae
GenusPinus
Speciesstrobus
CategoryWoody
TypeTree (evergreen)
Pronunciation

Details

USDA Hardiness Zone3 - 8
USDA Hardiness Ref.
Canadian Hardiness Zone1a - 6b
Canada Hardiness Ref.
RHS Hardiness ZoneH5 - H7
RHS Hardiness Ref.
Temperature (°C)-40 - (-15)
Temperature (°F)-40 - 5
Height15 - 25 m
Spread7 - 14 m
GrowthFast
Flowering PeriodMay

Description and Growing Information

General DescriptionThe older it grows the more windswept it looks.
ID CharacteristicThe only pine native to Eastern North America with five needles.
ShapeConical in its youth with a flatter top at maturity.
CultivationPrefers moist sandy loam in full sunlight although seedlings are shade tolerant until about 20 years old.
PestsThe White Pine blister rust, web worm, saw fly, European pine beetle, White Pine weevil can be minor problems.
Notable SpecimensThe A.M. Cuddy Gardens, Strathroy, Ontario, Canada. The Niagara Parks Botanical Gardens, Niagara Falls Ontario, Canada and The Royal Botanical Gardens, Burlington, Ontario, Canada.
HabitatAnywhere from rocky ridges to sphagnum bogs to dry sandy soils.
Bark/Stem DescriptionFissured, at maturity and silver in colour often with heavy resin deposits where branches have been removed or broken. In its youth the bark in often light green, but turns grey-brown and scaly with age.
Flower/Leaf Bud DescriptionThe buds are red-brown in colour with overlapping scales and are sharply pointed to 15 mm long.
Leaf DescriptionSoft and flexible with five, 12 cm needles per fascicle that persist for one to four years: blue green with white dots.
Flower DescriptionSmall, yellow male strobili cluster at the base of the first year's growth; light brown female strobili turn woody once mature, cones are 8-20 cm long and are often slightly curved.
Fruit DescriptionCones are roughly 15 cm in length, pointed, course, narrow, and resinous. Yellow-green and turning to light brown in September when the cones mature and then drop from the plant during the autumn and winter months.
Colour DescriptionBlue-green needles with silver bark and resin deposits covering almost all parts of the plant.

Photographs