Home Native Plant Network
NPN Protocol Details Image

Acer (glabrum)

Tara Luna
USDI NPS - Glacier National Park
West Glacier, Montana 59936
(406) 888-7835

Family Scientific Name: ACERACEAE
Family Common Name: Maple Family
Scientific Name: Acer glabrum Torr. glabrum Hook.
Common Synonym: Acer douglasii Hook.
Common Name: Rocky Mountain Maple
Species Code: ACEGLA
Ecotype: Lake McDonald, 1000 m elevation
General Distribution: Acer glabrum occurs from Alaska to California, east to Alberta and south through the Rockies to New Mexico, also in Nebraska. It commonly occurs as an understory species in many coniferous forest types, upland deciduous and riparian forests and in a variety of mixed shrub vegetation on open mountain slopes.
Propagation Goal: plants
Propagation Method: seed
ProductType: Container (plug)
Stock Type: 172 ml conetainers
Time To Grow: 10 Months
Target Specifications: Height: 20 cm Caliper: 1.7 cm Root System: Firm plug in 3L containers.
Propagule Collection: Timing of seed collection plays an important role in germination success. The fruit is an indehiscent samara that is 2.5 to 3.0 cm (1.0 to 1.5 in) long with papery wings. Ripe samaras are greenish to light brown and still somewhat leathery. Mature samaras are firm with yellow cotyledons completely filling the seed cavity. Generally, seeds are at the optimum stage for collection in early August at moderate elevations and early September at higher elevations.
It is important to perform a cut test prior to collection. Samaras must be collected before the pericarp becomes withered, dry and hard. Samaras with hardened pericarps collected in late fall germinate poorly.
Seeds can be hand collected or by flailing branches over a tarp spread on the ground.
Seeds are collected in paper bags.
Collection Locality: Avalanche, Glacier National Park
Propagule Processing: Seeds are placed into a prologed water soak immediately after collection. It is important not to store seeds for further drying after collection.Acer seeds have both physiological and seed coat dormancy which are often difficult to overcome. Many species are classified as being in deep dormancy.

Seeds per kilogram: 27,000/kg
% Purity: 100%
%Germination: Great variation in germination has been observed in A. glabrum in 10 years of production at Glacier; ranging from 1 to 50%. Timing of seed collection determines the toughness of the pericarp and accounts for range in germination percentages.
Pre-Planting Treatments: It is important that seeds are placed in water immediately after collection for 3 days to 1 week. This prolonged soaking helps to soften and hydrate seeds with tough leathery pericarps prior to stratification. During soaking, water must be changed once or twice per day.
Seeds are placed in a 90 day warm, moist stratification (23 to 25C) followed by 120 day cold, moist stratification at 1 to 3C. Imbibed seeds are sown in trays and lightly covered or placed in fine mesh bags buried in moist peat moss in ventilated containers.
Growing Area Preparation/
Annual Practices for Perennial Crops:
Greenhouse and Outdoor nursery growing facility.

Sowing Method: Planting Germinants. Germinated seeds are sown into 172 ml Ray Leach conetainers as soon as radicle emerges from the seed coat.
Growing medium used is milled sphagnum peat, perlite, and vermiculite with Osmocote controlled release fertilizer (13N:13P2O5:13K2O; 8 to 9 month release rate at 21C) and Micromax fertilizer (12%S,0 .1%B, 0.5%Cu, 12%Fe, 2.5%Mn, 0.05%Mo, 1%Zn) at the rate of 1 gram of Osmocite and 0.20 gram of Micromax per 172 ml conetainer.
Establishment Phase: Germination is non-uniform and is usually complete in 4 weeks. True leaves appear 2 weeks after germination.
Length of Establishment Phase: 4 weeks
Active Growth Phase: Seedlings grow at a rapid rate after establishment. Seedlings are fertilized with 20-20-20 NPK liquid fertilizer at 100 ppm during the growing season. Plants can be uppotted into 3L(1 gallon) containers 9 weeks after germination, and be root tight in 4 months.
Length of Active Growth Phase: 16 weeks
Hardening Phase: Plants are fertilized with 10-20-20 NPK in liquid fertilizer at 200 ppm in the fall, pots are leached with clear water, one final irrigation is applied before overwintering.
Length of Hardening Phase: 6 weeks
Harvesting, Storage and Shipping: Total Time to Harvest: 10 months
Harvest Date: September
Storage Conditions: Overwinter in outdoor nursery under insulating foam cover and snow.
Length of Storage: 5 months
Other Comments: This species is a long lived, tolerant seral species, and is found in the understory of late seral or climax forests, riparian zones, and seral, fire dependent shrub communities. It has the ability to resprout following a fire.
Some shade is required for establishment.
There are two botanical varieties that occur in Glacier National Park; var. glabrum and var. douglasii.
References: Flora of the Pacific Northwest, Hitchcock and Cronquist, University of Washington Press, 7th printing, 1985.
Seeds of the Woody Plants in the United States, Agriculture Handbook No. 450, U.S.F.S., Washington D.C., 1974.
Seeds of Woody Plants in North America, Young and Young, Dioscorides Press, 1992.
Seed Germination Theory and Practice, 2nd Edition, Deno, N., published June,1993.
Glacier Park Native Plant Nursery Propagation Records, unpublished.
The Fire Effects Information System. Missoula, MT: USDA Forest Service, Intermountain Fire Sciences Laboratory.


Luna, Tara; Evans, Jeff; Wick, Dale; Hosokawa, Joy. 2008. Propagation protocol for production of Container (plug) Acer glabrum Torr. plants 172 ml conetainers; USDI NPS - Glacier National Park West Glacier, Montana. In: Native Plant Network. URL: http://NativePlantNetwork.org (accessed 2021/07/27). US Department of Agriculture, Forest Service, National Center for Reforestation, Nurseries, and Genetic Resources.

Personal tools