Practical ecological knowledge for the temperate reader.

Acer glabrum - Douglas Maple


Subtaxa present in B.C.
Acer glabrum var. douglasii [IFBC-E-flora]

"Acer glabrum is a deciduous Tree growing to 9 m (29ft 6in) at a slow rate.
It is hardy to zone 5. It is in flower in April, and the seeds ripen in September. The flowers are dioecious (individual flowers are either male or female, but only one sex is to be found on any one plant so both male and female plants must be grown if seed is required) and are pollinated by Insects." [PFAF]
"Suitable for: light (sandy), medium (loamy) and heavy (clay) soils, prefers well-drained soil and can grow in heavy clay soil. Suitable pH: acid, neutral and basic (alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil." [PFAF]

"Douglas maple is the only member of the maple family (Aceraceae) native in Alaska. Named for its discoverer, David Douglas (1798-1834), Scotch botanical explorer, who introduced many trees from western North America to Europe." [Viereck ATS]

USDA Flower Colour: Green Blooming Period: Late Spring
USDA Fruit/Seed characteristics: Colour: Brown Present from Summer to Fall [E-flora] USDA hardiness zone: 3-8 [PFAF]

Ecological Indicator Information: A shade-tolerant to shade-intolerant, montane to subalpine, Western North American deciduous shrub distributed more in the Cordilleran than the Pacific region. Occurs on nitrogen-rich, water-shedding and water-receiving sites within continental boreal, cool temperate, cool semiarid, and occasionally cool mesothermal climates. Scattered throughout coastal British Columbia; its occurrence increases with increasing continentality. Common on eastern Vancouver Island and in Skeena River valley. Grows with vine maple in the southem coast-interior ecotone. Like A. circinatum, it inhabits open-canopy forests, clearings, and primary succession stages on fragmental colluvial soils. Regenerates abundantly from stump sprouts; it hinders regeneration and growth of shade­intolerant conifers. Characteristic of Moder and Mull humus forms. [IPBC][E-flora]

Edible Uses

Other Uses

Medicinal Uses


"Landscape Uses: Erosion control, Massing. Of easy cultivation, it succeeds in any soil, preferring a good moist well-drained soil[11]. Prefers a sunny position but tolerates some shade[11, 200]. Grows well in heavy clay soils. Chlorosis can sometimes develop as a result of iron deficiency when the plants are grown in alkaline soils, but in general maples are not fussy as to soil pH. Hardy to about -25oc[184]. This species grows well at Kew, a specimen was 12 metres tall in 1967[11]. The tree is almost fastigiate[11]. Most maples are bad companion plants, inhibiting the growth of nearby plants[18, 20]. Trees are usually dioecious. Male and female trees must be grown if seed is required[226]." [PFAF] "Due to its flexible stems, it can withstand heavy snow pack and often codominates avalanche chutes. Its range is from southern Alaska to New Mexico (Elias 1980, Uchytil 1989)." [PPNWNP]
"Rocky Mountain maple seedlings grow about 30 cm/year (Hansen 2003). On good sites sprouts may reach 1.3 m within 2 years and 3 m in 10 years. Maximum heights are reached in 30 to 40 years (Anderson 2001).... It is an important browse species for domestic livestock, especially sheep, and wild ungulates. Samples of summer growth contained about 8.7 percent crude protein, 3.1 percent fat, 34.0 percent crude fiber, 51.0 percent N-free extract, and 3.2 percent ash. Samples of winter browse contained 5.9 percent crude protein, 2.4 percent fat, 33.3 percent crude fiber, and 54.2 percent N-free extract (Anderson 2001). The seeds and vegetative parts are consumed by ruffed and blue grouse, grosbeaks, and small mammals (Anderson 2001)." [Francis,2004]


"Seed - best sown as soon as it is ripe in a cold frame, it usually germinates in the following spring. Pre-soak stored seed for 24 hours and then stratify for 2 - 4 months at 1 - 8°c. The seed has a hard coat and can be slow to germinate, often taking 2 years. The seed can be harvested 'green' (when it has fully developed but before it has dried and produced any germination inhibitors) and sown immediately. It should germinate in late winter. If the seed is harvested too soon it will produce very weak plants or no plants at all[80, 113]. When large enough to handle, prick the seedlings out into individual pots and grow them on until they are 20cm or more tall before planting them out in their permanent positions. Layering, which takes about 12 months, is successful with most species in this genus. Cuttings of young shoots in June or July. The cuttings should have 2 - 3 pairs of leaves, plus one pair of buds at the base. Remove a very thin slice of bark at the base of the cutting, rooting is improved if a rooting hormone is used. The rooted cuttings must show new growth during the summer before being potted up otherwise they are unlikely to survive the winter. It is very difficult to find suitable wood for cuttings." [PFAF] Seed: "Douglas maple begins to produce seed as early as ten years of age. Seeds reach maturity from August through early October. Hand picking of the samaras is the best method of collection. Clean by hand rubbing or hammermilling of the wings and blowing off chaff. Dry the seeds to 10-15% moisture content and store at 2-5°C in sealed containers. Warm stratification for 180 days followed by cold stratification for 180 days gives a 25% germination rate in container seeding in a greenhouse. Seed can also be sown by direct field planting in the fall (Olson and Gabriel 1974)." [PPNWNP]Vegetative: "Douglas maple sprouts easily from root crowns following a disturbance (Olson and Gabriel 1974)." [PPNWNP]


  1. [E-flora] Acer glabrum,, Accessed July 29, 2017
  2. Francis,2004 - Wildland Shrubs of the United States and Its Territories: Thamnic Descriptions: Volume 1, USDA Forest Service John K. Francis, Editor, July 2004
  3. Gottesfeld1992 - The Importance of Bark Products in the Aboriginal Economies of Northwestern British Columbia, Canada, Leslie M. Johnson Gottesfeld, Economic Botany 46(2) pp. 148-157, 1992
  4. [PFAF] Acer glabrum Plants For A Future,, U.K., Accessed May 12, 2014
  5. Turner1990 - Contemporary Use of Bark for Medicine by two Salishan Native Elders of Southeast Vancouver Island, Canada, Nancy J. Turner and Richard J. Hebda, Journal of Ethnopharmaology, 29 (1990) 59-72, Elsevier Scientific Publishers Ireland Ltd.
  6. Turner&Burton - Soapberry: Unique Northwestern Foaming Fruit, Nancy J. Turner and Carla M. Burton
  7. [Turner, Kuhnlein] Traditional Plant Foods of Canadian Indigenous Peoples, Harriet V. Kuhnlein & Nancy J. Turner, Gordon and Beach Publishers, Netherlands, 1991

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