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Protocol Information

Native Plant Nursery
USDI NPS - Glacier National Park
West Glacier, Montana 59936
(406) 888-7835

Family Scientific Name: Pinaceae
Family Common Name: Pine family
Scientific Name: Pinus flexilis James
Common Name: Limber pine
Species Code: PINFLE
Ecotype: Rising Sun, Glacier National Park, Glacier Co., MT.,1585m elev. 
General Distribution: P. flexilis occurs at or near treeline in mostly semi-arid ranges from southeast B.C. to southwest Alberta and the Dakotas, south in Idaho and Montana to New Mexico, California, Nevada. It is also found in northeastern Oregon. It occurs east of the Continental Divide in Glacier National Park.
Propagation Goal: Plants
Propagation Method: Seed
Product Type: Container (plug)
Stock Type: 172 ml Conetainers
Time To Grow: 20 Months
Target Specifications: Stock Type: Container seedling.
Height:9.0 cm
Caliper:8 mm
Root System: Firm plug in container.
Propagule Collection: Cones are collected in late September when cones are yellowish brown and before cone scales are opened. Cones are cut from branches using pruning poles and hand pruners. Cones are kept in burlap sacks in the drying shed prior to cleaning. Seeds are brown at maturity.
Propagule Processing: Seeds are easily extracted from opened cones using a tumbler. Seeds are dewinged and stored at 0C.
Seed longevity is up to 5 years at 0C in sealed containers.
Seed dormancy is classified as physiological dormancy.
Seeds/Kg: 22,000/kg
% Purity: 100%
% Germination: 68 to 80%
Pre-Planting Treatments: Seeds were cleansed with a 8 minute 3:1 (v:v)water/bleach soak followed by a 48 hour running water rinse and a 45 to 100 day cold, moist stratification.
Seeds are placed in fine mesh bags buried in moist peat moss in ventilated containers under refrigeration at 3C.
Growing Area Preparation/
Annual Practices for Perennial Crops:

Greenhouse and outdoor nursery growing facility.
Sowing Method: Direct Seeding. Seeds are covered with medium.
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 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.
Establishment Phase: Seedings emerge 7 to 10 days after sowing. Seedlings are thinned at the bird cage stage. Germinants shed seedcoats 15 days after emergence.
It is important to allow medum to dry slightly after seedlings are established.This prevents pre and post emergence damping off disease and other root diseases.
Seedlings are fertilized with Conifer Starter 7-40-17 liquid NPK at 50 ppm for 1 month.
Length of Establishment Phase: 4 weeks
Active Growth Phase: Seedlings reach the rapid growth stage 4 to 5 weeks after germination.
Average height was 5 centimeters 4 months after germination. Plants attained root-tightness 6 months after germination.
Plants were regularly fertilized with 20-7-19 liquid NPK at 200 ppm. Plants are moved from the greenhouse to the outdoor nursery 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; pots 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: 1.8 years
Harvest Date: September of the second year
Storage Conditions: Overwinter in outdoor nursery under insulating foam cover and snow.
Length of Storage: 5 months
Other Comments: 3 L (1 gallon) container stock can be produced in 2.5 years with an average height of 15 cm and 8 mm caliper.
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 Plants of the U.S., Agriculture Handbook #450, U.S.F.S., Washington D.C., 1974.

Evans, Jeff; Luna, Tara.; Wick, Dale. 2008. Propagation protocol for production of container Pinus flexilis James plants (172 ml Conetainers); USDI NPS - Glacier National Park, West Glacier, Montana. In: Native Plant Network. URL: http://www.nativeplantnetwork.org (accessed 30 August 2015). Moscow (ID): University of Idaho, College of Natural Resources, Forest Research Nursery.