Pacific madrone (Arbutus menziesii): what the agencies record

This page reports what US federal publications say about one tree. It does not identify trees from descriptions or photos and does not say what should be done with any tree. The family overview, tree species in the agency records, explains the sources and holds the comparison table. Two related pages: tanoak, which shares its forest cover type, and fall webworm, an insect the madrone chapter names.

At a glance

Item	What the source records
Scientific name	Arbutus menziesii Pursh, heath family (Silvics and PLANTS, symbol ARME)
Other names, Silvics	Arbutus in Canada; madrone, madroda or madrono in the United States
Native status, USDA PLANTS	Native in Canada and the lower 48 states
Size, Silvics	Seldom over 34 m (110 ft) tall and 152 cm (60 in) in breast-height diameter; the largest on record is in Humboldt County, California, 24 m (79 ft) tall with a circumference of over 975 cm (384 in) 0.9 m (3 ft) above ground
Green weight of the wood, NRS-38	60 lb per cubic foot, without bark (Table 1A); green specific gravity 0.58
Shrinkage green to ovendry, Wood Handbook Table 4-3	Radial 5.6 percent, tangential 12.4 percent, volumetric 18.1 percent

Native range and climate

The Silvics of North America handbook (Agriculture Handbook 654, Volume 2, 1990) says Pacific madrone ranges from the east coast of Vancouver Island and the nearby British Columbia mainland (latitude 50 degrees N) south to near Palomar Mountain, San Diego County, California (latitude 33 degrees N), a distance of 1,880 km (1,170 mi). It is common on Coast Range western slopes in Washington, Oregon and California south to San Luis Obispo County, abundant through much of the Klamath Mountains, and found in the Sierra Nevada from Yuba County south through Calaveras County.

The handbook describes mild, cloudy, wet winters and cool, fairly dry summers in the north, with 75 to 85 percent of the 790 to over 3,000 mm (31 to 118 in) of yearly precipitation falling between October 1 and March 1. Across the whole range it gives temperature extremes of minus 21 to 46 degrees C (minus 6 to 115 degrees F) and annual rainfall from 460 to 4,220 mm (18 to 166 in). Silvics says madrone ranks among the better trees at drawing moisture from the soil, was placed fifth to seventh of 23 species for drought tolerance, and is judged the least frost-resistant tree native to British Columbia.

Soils and forest cover

Silvics reports soils from glacial sands and gravels in the north to volcanic and metamorphosed rocks in the Klamath Mountains, volcanic and sedimentary rocks in the California Coast Ranges, and granitic rocks in the Sierra Nevada. Most madrones grow on Alfisols. Soils range from loams to gravelly sandy loams, are often under 1 m (3.3 ft) deep, drain well internally and hold little moisture in summer. In California the handbook counts more than 30 soil series carrying the species. Madrone grows from sea level in the north to 1,300 m (4,260 ft) in the California Coast Ranges, on all aspects but most often south and west. Silvics names Douglas-fir-Tanoak-Pacific Madrone (Society of American Foresters type 234) as the forest cover type in which madrone is a major part, and says it grows singly or in groves and rarely forms large stands.

Flowers, berries and seedlings

The handbook describes small whitish urn-shaped flowers that open from mid-March at low elevations to mid-May higher up, with flowering usually ending in June. The fruit is a berry 8 to 12 mm (0.3 to 0.5 in) across, bright red or reddish-orange when ripe, maturing from mid-September to mid-November, with 2 to 37 seeds. Trees first bear berries at 3 to 5 years, and Silvics says trees 60 to 160 years old produce heavy crops if healthy. On one Sierra Nevada site over 1958 to 1977 the handbook counts 2 bumper seed years, 8 light years and 10 with little or no seed. Birds, rodents, deer and wood rats eat the berries; berries made up more than 17 percent of the November diet of band-tailed pigeons in one study.

Silvics says seedlings are not abundant. In a Santa Cruz Mountains study, fungus attack directly killed 28 percent of seedlings and root decay fungi followed by mild drought another 22.7 percent, and none of 276 seedlings on shady plots survived. In southwestern Oregon, first-year seedling mortality was 90 to 100 percent. Seedlings mostly start in disturbed ground such as road cuts, on bare mineral soil, or in semi-open forest. The handbook calls early growth slow, with two-year-old Sierra Nevada seedlings averaging 9 cm (3.5 in) tall.

Sprouting, growth and age

Pacific madrone reproduces mainly by sprouting from dormant buds at or just above the root collar. More than 300 sprouts were counted on one low stump 10 inches across. Silvics says low stumps produce more sprouts than high ones, and that stool sprouts on high stumps tend to get heart rot early. Sprouts grow fast: three-year-old clumps in the Klamath Mountains averaged 13 stems and 3.1 m (10 ft) in height, and in the northern Sierra Nevada, ten-year-old clumps in a clearcut were 6.7 m (22 ft) tall. The handbook says most trees observed come from sprouts, and that position in the clump governs form.

It calls madrone usually a tall, straight tree in forested canyons and often low, shrubby and multi-stemmed on poor south-facing ridges. Growth in diameter is slow, 5 to 6 rings per centimeter (12 to 15 per inch) on good Sierra Nevada sites. Trees 200 to 250 years old are on record and large ones are estimated at 400 to 500 years. Trees 50 to 60 years old often have a root burl, and large ones 61 to 91 cm (24 to 36 in) across can have burls 122 to 152 cm (48 to 60 in) wide. Silvics classes shade tolerance as intermediate and the species as probably more subclimax than climax.

Damaging agents the handbook names

Fire. Silvics calls fire a major damaging agent to the thin bark. Seedlings, sprouts and trees die back to the root crown but are rarely killed, while competing conifers are usually badly damaged or killed.
Insects and animals. The handbook calls insect damage minor and not economically significant. It names the leaf miner Marmara arbutiella and says the fall webworm commonly deforms young trees and sprouts. Deer eat berries and browse young shoots, with minor damage.
Madrone canker. The handbook names Fusicoccum aesculi (Botryosphaeria dothidea) as a major cause of dieback and death, starting at branch tips with a dark wine-red bark discoloration that turns black, and then forming a wedge-shaped canker that can encircle and kill the branch. It says the disease had become a serious problem in northern California in the 10 to 12 years before 1990 and had been seen in Oregon and Washington.
Other cankers and root disease. Phytophthora cactorum cankers start at the groundline and spread up the trunk; Hendersonula toruloidea cankers are fairly widespread on madrone in British Columbia; and annosus root rot killed more than 100 trees in Amador County, California, in 1976.
Heartwood rots. Phellinus igniarius, Fomitopsis cajanderi and Poria subacida are named as the most important, and Silvics notes that living madrones with infected heartwood are heavily used by cavity-nesting birds.

For who takes reports of regulated pests, see reporting a pest in the United States, and pests and diseases by country sets out which ones agencies regulate.

Wood and other uses

Silvics describes the wood as moderately dense and strong and extremely hard, and says dry wood resembles black cherry in colour, grain and figure and looks good as rotary-cut veneer. It lists bobbins, shuttles, novelties, tobacco pipes, furniture, paneling, flooring, interior trim, charcoal and fuelwood among uses, and says early Californians preferred madrone charcoal for gunpowder. The Wood Handbook (FPL-GTR-282, 2021) has no strength-table row or species description for Pacific madrone; the shrinkage figures above come from its Table 4-3. The handbook also notes the smooth reddish-orange bark, shiny leaves and colorful berries led to its use as an ornamental, and says no natural varieties or hybrids are known.