Douglas firs are among the tallest trees on Earth, and in the Pacific Northwest few trees outgrow them. How tall yours gets depends mostly on which of two forms it is, the wet-coast type or the dry-mountain type. The tallest ever reported may even have been taller than any redwood alive today, though those old claims are disputed.1Wikipedia. Nooksack Giant
Typical Heights for Coast and Rocky Mountain Douglas Firs
Coast Douglas fir grows in wet coastal and inland areas from California into British Columbia.2Pacific Forest Trust. Douglas Fir In good forest it can reach about 250 feet tall and 5 to 6 feet across the trunk.3Pacific Forest Trust. Douglas Fir A few coast trees pass 300 feet.4Treehugger. How to Identify Douglas Fir Trees Those heights belong to old-growth, meaning old, never-logged forest where trees have stood for centuries.
Rocky Mountain Douglas fir grows on cool, dry mountain ranges from New Mexico into Canada.5Pacific Forest Trust. Douglas Fir It usually reaches about 115 to 150 feet and around 3 feet across.6Pacific Forest Trust. Douglas Fir Many never get past about 130 feet.7Treehugger. How to Identify Douglas Fir Trees An inland tree is often 100 feet or more shorter than a coastal one.8WorldAtlas. Why Douglas Firs Grow Taller On The Coast Than Inland
In a yard, expect the low end of your variety’s range, often well under forest maximums. Plan around a realistic yard height rather than the forest record.
Location is the best clue to which type you have. West of the Cascades and along coastal British Columbia, it’s the coast type. Trees on dry interior mountains from Montana to New Mexico are the Rocky Mountain type, which often looks bluer-green and grows more compact. Nursery labels may say “var. glauca” for the inland form.
Height depends on the site as much as the variety. Two coast trees a mile apart can differ by dozens of feet. Crowding matters too: trees in dense forest race upward for light, while a lone yard tree spreads wider and stays shorter. When a source gives a single “average,” it usually blends young and mature trees, so ask what age and setting it describes.
Coast Douglas firs regularly live more than 500 years, and the oldest pass 1,300.9WorldAtlas. Why Douglas Firs Grow Taller On The Coast Than Inland Inland trees rarely live beyond 400 years.10WorldAtlas. Why Douglas Firs Grow Taller On The Coast Than Inland Trunk width rises roughly along with height, so a very wide trunk often belongs to an older, larger tree. But a tree with a broken or dead top can be thick and still fairly short, so width hints at age without telling you the height.
Why Coastal Douglas Firs Grow So Much Taller
Coastal moisture, stable temperatures and good soil let coast trees approach their variety’s full height.11WorldAtlas. Why Douglas Firs Grow Taller On The Coast Than Inland These trees also carry inherited adaptations to that wet climate.12WorldAtlas. Why Douglas Firs Grow Taller On The Coast Than Inland Inland trees, by contrast, grow on drier, higher sites, from about 1,600 to over 10,000 feet up.13Elsevier / Quaternary Science Reviews. Glacial populations and postglacial migration of Douglas-fir based on fossil pollen and macrofossil evidence
Coastal summers are cool and often foggy, so trees lose less water to heat just when growth matters most. Winters are wet and mild, which refills the soil before the dry months arrive. Inland sites swing between colder winters and hotter, drier summers, which shortens the season when a tree can grow well.
Douglas fir growth suffers when summer rain falls below about 270 mm, roughly 11 inches.14PubMed Central. Forest stand productivity derived from site conditions: an assessment of old Douglas-fir stands (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) in Central Europe Growth is best at average summer temperatures of about 17 to 18 °C (63 to 64 °F) and falls in hotter summers.15PubMed Central. Forest stand productivity derived from site conditions: an assessment of old Douglas-fir stands (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) in Central Europe More rain beyond that point does not add growth.16PubMed Central. Forest stand productivity derived from site conditions: an assessment of old Douglas-fir stands (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) in Central Europe Very sandy soil, over about 45% sand, holds less water and lowers growth.17PubMed Central. Forest stand productivity derived from site conditions: an assessment of old Douglas-fir stands (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) in Central Europe
For your own tree, deep watering in dry summers helps a young one most. Care alone can’t turn an inland tree into a coastal giant.
The Tallest Douglas Fir Alive Today
The Doerner Fir, a coast Douglas fir in Coos County, Oregon, measured 325.8 feet in 2022.18Wikipedia. Doerner Fir It had stood 329 feet in 1991 but lost about 3 feet of its top.19Wikipedia. Doerner Fir On its sloping site the trunk runs about 10 feet further downhill, making it about 339 feet from lowest point to tip.20Wikipedia. Doerner Fir It is one of the tallest trees in the world that is not a redwood.21Wikipedia. Doerner Fir Record trees lose height because tops break in storms and heavy snow, and a top can die back in dry years.
Height is normally measured from the highest ground at the base up to the tip, which is why the downhill figure is given separately. The sloped-site number is real, but it counts the trunk, so it shouldn’t be compared directly with other trees’ listed heights.
A record claim is checked by climbing the tree or measuring from the ground with a laser rangefinder, then repeating the work to catch errors. The highest tip is often hidden in the crown, so careful measurers check from several angles. That’s why a figure like 325.8 feet is reported to a tenth of a foot and tied to a specific year.
Coast redwoods are by far the tallest trees on the planet.22University of Georgia Warnell School of Forestry & Natural Resources. Extreme Trees: Tallest, Biggest, Oldest Among confirmed tallest species, Douglas fir ranks behind redwood, a Himalayan cypress in Tibet, a tropical meranti and some eucalyptus.23University of Georgia Warnell School of Forestry & Natural Resources. Extreme Trees: Tallest, Biggest, Oldest
Many record trees stand on public forest land, though exact locations are sometimes kept quiet to protect roots from trampling. Stay on trails and avoid compacting the soil around the base.
Historical Douglas Firs Over 400 Feet
The Mineral Tree in Lewis County, Washington, measured 393 feet tall and 15.4 feet across.24HistoryLink. The Mineral Tree, a 393-foot Douglas fir in Lewis County, falls in 19 That makes it the tallest Douglas fir officially documented in Washington history.25HistoryLink. The Mineral Tree, a 393-foot Douglas fir in Lewis County, falls in 19 A documented height is one where someone measured the tree with a recognized method and recorded the result so others can check it.
Reports from the 1890s to 1920s describe about 100 Douglas firs around Puget Sound said to be 350 to 400 feet.26Wikipedia. Nooksack Giant Then came the Nooksack Giant, reported at 465 feet, which would beat any tree reliably measured anywhere.27Wikipedia. Nooksack Giant Experts doubt that figure because it sits near the species’ physical limit and was barely verified.28HistoryLink. The Mineral Tree, a 393-foot Douglas fir in Lewis County, falls in 19 Early estimates were often eyeballed by “good judges.” Some were exaggerated, but not all.
Lumber offers a check, though. The Nooksack Giant’s lumber, over 96,000 board feet compared with about 60,000 from a typical 350-foot tree, suggests a tree of about 400 feet is plausible, though not the full 465.29Wikipedia. Nooksack Giant Even a 415-foot tree measured in 1902 has disputed figures.30Wikipedia. Nooksack Giant
The old giants are gone because most of the tallest trees grew in valley forests that were logged early, and loggers prized the biggest trees for timber. Claims often rest on stump signs and stories rather than repeat measurements, so many remain stories even if the tree really was enormous.
How Tall a Douglas Fir Could Ever Grow
Water in a tree is pulled upward from the roots through narrow tubes of wood, not pushed from below. The higher a tree grows, the harder that water is pulled against gravity and friction.31Proceedings of the National Academy of Sciences. Maximum height in a conifer is associated with conflicting requirements for xylem design
That stretching puts tall trees at risk of air bubbles forming in their water pipes and blocking the flow.32BBC News. How Tall Are Douglas Fir Trees? From Average to Record A blocked tube cannot carry water again, so the tree loses some supply. To stay safe, the openings between wood cells get smaller with height, which slows water.33BBC News. How Tall Are Douglas Fir Trees? From Average to Record Water flow would reach near zero at about 358 feet in the trunk and 453 feet in branches.34PubMed Central. Maximum height in a conifer is associated with conflicting requirements for xylem design That matches historic records of about 330 to 415 feet for the species.35PubMed Central. Maximum height in a conifer is associated with conflicting requirements for xylem design
Near the limit, the top foliage suffers drought stress and dies back.36BBC News. How Tall Are Douglas Fir Trees? From Average to Record Still, top needles in tall trees keep working under drier conditions than lower needles do.37PubMed. Impacts of tree height on leaf hydraulic architecture and stomatal control in Douglas-fir In dry summers, tall trees’ tops still made food about as well as short trees’ tops.38PubMed. An investigation of hydraulic limitation and compensation in large, old Douglas-fir trees
A thin or dead top can show a tree near its height limit or recovering from a dry spell. Old firs often stop climbing and grow wider instead, and a dead top is not always a sign the whole tree is dying. A sudden top die-back in a yard tree is worth an arborist’s look.
How Fast Douglas Firs Grow and When They Stop
Young Douglas firs in good conditions often add one to two feet a year. Growth is fastest in the first several decades, and full height takes centuries in forest settings. Forests logged on short cycles never grow trees anywhere near record size.
Height growth slows because the tree gets big, not because it gets old.39PubMed. Developmental decline in height growth in Douglas-fir Each new foot costs more than the last, since the tree must lift water farther and support more wood. The proof is that shoots cut from old giants grew up to 10 times faster within 2 years once grafted onto young roots.40PubMed. Developmental decline in height growth in Douglas-fir
Old coast Douglas firs keep renewing their foliage after they stop growing taller.41Canadian Journal of Botany. The role of epicormic shoot production in maintaining foliage in old Pseudotsuga menziesii (Douglas-fir) trees Upper branches still grow, while lower ones are kept alive by new sprouts along the branches.42Canadian Journal of Botany. The role of epicormic shoot production in maintaining foliage in old Pseudotsuga menziesii (Douglas-fir) trees The crown stays alive instead of thinning, and this renewal may help them live for centuries.43Canadian Journal of Botany. The role of epicormic shoot production in maintaining foliage in old Pseudotsuga menziesii (Douglas-fir) trees
How to Estimate a Douglas Fir’s Height Yourself
Careful ground measurements of Douglas firs can come within about a foot of the true height.44Canadian Journal of Remote Sensing. A rigorous assessment of tree height measurements obtained using airborne lidar and conventional field methods Airborne laser scans usually read Douglas firs about 3 feet short.45Canadian Journal of Remote Sensing. A rigorous assessment of tree height measurements obtained using airborne lidar and conventional field methods A common shortcut method underestimated heights by about 20% on average.46Methods in Ecology and Evolution. Measuring tree height: a quantitative comparison of two common field methods in a moist tropical forest The other common angle method occasionally doubled the real height when done poorly.47Methods in Ecology and Evolution. Measuring tree height: a quantitative comparison of two common field methods in a moist tropical forest
A tall Douglas fir has a narrow, pointed crown, so the real tip can be hard to pick out. Brush or uneven ground can hide the base too, which is why even skilled measurers end up off by a few feet.
For the stick method, hold a stick at arm’s length with the length above your hand equal to your arm’s length. Walk back until the stick spans the tree from base to tip. Your distance to the trunk then roughly equals the tree’s height, measured from eye level, so add your eye height. Level ground works best.
A phone app or clinometer measures the angle from your eye up to the treetop, and sometimes down to the base. With a known distance to the trunk, the height follows from that angle. Hold the device steady and aim at the highest point you can honestly identify.
The usual mistake is aiming too low because branches hide the true top. Standing on a slope throws off angle readings, so measure from several spots and average the results.