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Tsuga (heterophylla)

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

Family Scientific Name: Pinaceae
Family Common Name: Pine family
Scientific Name: Tsuga heterophylla (Raf.) Sarg.
Common Name: Western hemlock
Species Code: TSUHET
Ecotype: Avalanche, Glacier National Park, MT. 1100 meters elevation
General Distribution: T. heterophylla occurs from sea level to 1550 m elevation, in mesic to wet coastal and montane forests. It ranges from Alaska to northern California, east to southeast B.C., northern Idaho, and northwestern Montana.
Propagation Goal: plants
Propagation Method: seed
ProductType: Container (plug)
Stock Type: 172 ml conetainers
Time To Grow: 19 Months
Target Specifications: Stock Type: Container seedling<br> Height: 7.0 cm<br> Caliper: 7 mm<br> Root System: Firm plug in container.
Propagule Collection: Cones are collected in late September using pruning poles when cones are brown and before scales begin to reflex. Seeds are light tan at maturity. Cones are kept in burlap bags in drying shed prior to cleaning.
Propagule Processing: Seeds are easily extracted from opened cones using a tumbler. Wings are removed in a fanning mill.
Seed longevity is up to 5 years at 0C in sealed containers.
Seed dormancy is classified as physiological dormancy.
Seeds/Kg: 572,000/kg.
% Purity: 100%
% Germination: 52%
Pre-Planting Treatments: Seeds are placed into a 48 hour running water rinse. Do not bleach treat seeds.
After pretreatment, seeds are placed in a 45 day cold, moist stratification. Seeds are placed in fine mesh bags and buried in moist peat moss in ventiliated containers at 3C.
Growing Area Preparation/
Annual Practices for Perennial Crops:
Greenhouse and Outdoor Nursery growing facility.
Sowing Method: Direct Seeding. Seeds must be surface sown for light requirement.
Growing medium used is 6:1:1 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 Osmocote and 0.20 gram of Micromax per 172 ml conetainer.

Greenhouse temperatures are maintained at 21 to 25C during the day and 16 to 18C at night. Seedlings are hand watered and remain in greenhouse until mid May. Seedlings are then moved to outdoor nursery for the remainder of the growing season.
Seedlings are irrigated with Rainbird automatic irrigation system in early morning until containers are thoroughly leached.
Average growing season of nursery is from late April after snowmelt until October 15th.
Establishment Phase: Germination was slow but uniform and is usually complete in 20 days. Seedlings are fertilized with Conifer Starter 7-40-17 liquid NPK fertilizer for 1 month.
Western hemlock seedlings are easily damaged by direct sun. Seedlings must be shaded throughout production.
Length of Establishment Phase: 4 weeks
Active Growth Phase: Seedlings reach the rapid growth stage 4 to 5 weeks after germination. Optimum growth and development occurs at air temperatures maintained at 18 to 23C. Average height was 14 centimeters 4 months after germination.
Plants attained root-tightness 6 months after germination. Plants were regularly fertilized with 20-7-19 liquid NPK during the active growth phase.
Plants are moved from the greenhouse to the outdoor shadehouse in late May.
Length of Active Growth Phase: 20 weeks
Hardening Phase: Plants are fertilized with 10-20-20 liquid NPK at 200 ppm in early fall. Conetainers are leached with water. Irrigation is gradually reduced through September and October.
Length of Hardening Phase: 4 weeks
Harvesting, Storage and Shipping: Total Time To Harvest: 1.7 years
Harvest Date: September of the second year.
Storage Conditions: Overwinter in outdoor shadehouse under insulating foam cover and snow.
Length of Storage: 5 months
Other Comments: 3L (1 gallon container) stock can be produced in 2 years.
Vegetative Propagation Method: Softwood cuttings taken in July have been successful on T. canadensis; using 8000 ppm IBA talc and wounding the base. Cuttings were placed under mist with bottom heat. Another study indicates cuttings taken in October and November have rooted to high percentages using a 5 second liquid dip of NAA and IBA at 5000 ppm each, with mist and bottom heat.
Western hemlock is also vegetatively propagated by grafting and layering.
References: Flora of the Pacific Northwest, Hitchcock and Cronquist, Univ. of Washington Press, 7th printing, 1990.
Seed Germination Theory and Practice, Second Edition, Deno, Norman, published 1993.
Glacier Park Native Plant Nursery Propagation Records, unpublished.
Seeds of the Woody Pants of North America, Young and Young, Dioscorides Press, 1992.
Seeds of the Woody Plants of the U.S., Agriculture Handbook #450, U.S.F.S., Washington D.C., 1974.
The Reference Manual for Woody Plant Propagation, Dirr, M., Varsity Press, 1986.


Luna, Tara; Evans, Jeff; Wick, Dale. 2008. Propagation protocol for production of Container (plug) Tsuga heterophylla (Raf.) Sarg. plants 172 ml conetainers; USDI NPS - Glacier National Park West Glacier, Montana. In: Native Plant Network. URL: http://NativePlantNetwork.org (accessed 2021/01/20). US Department of Agriculture, Forest Service, National Center for Reforestation, Nurseries, and Genetic Resources.

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