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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: Larix occidentalis Nutt.
Common Name: Western Larch
Species Code: LAROCC
Ecotype: Larch/Douglas-fir forest, West Glacier, Glacier National Park, Flathead Co., MT.,1100m elevation.
General Distribution: L. occidentalis occurs from the foothills to mid- montane zones and rarely to subalpine elevations. It ranges from southern B.C. to Deschutes Co., Oregon, east of the Cascades, east to northern Idaho, northwest Montana, and northeast Oregon. It is found on moist sites in well drained soils from 650 to 2450 meters. In Glacier, there are scattered trees east of the Continental Divide in the Two Medicine area.
Propagation Goal: Plants
Propagation Method: Seed
Product Type: Container (plug)
Stock Type: 172 ml conetainers
Time To Grow: 7 Months
Target Specifications: Stock Type: Container seedling
Height: 15 cm
Caliper: 6 mm
Root System: firm plug in conetainer.
Propagule Collection: Cones are collected in September and October when cones turn purplish brown and scales begin to reflex. Mature seeds are firm and dark brown to black in color. Cones are collected by cutting branches from trees. Collections are kept in paper bags. Cones are stored in a well ventilated drying shed prior to cleaning.
Propagule Processing: Larch seeds are reported to have higher germination percentage if seed is not extracted immediately from the cones. Cones should be dried in the sun or a well ventilated shed and tumbled to extract the seeds.
Seed Storage is at least 7 years at 0C in sealed containers.
Seed dormancy is classified as physiological dormancy.
Seeds/Kg: 300,000/kg
% Purity: 100%
% Germination: 70%
Pre-Planting Treatments: Seeds are placed into a 24 hour runnng water rinse prior to cold, moist stratification for 28 to 42 days.
Non-stratified seeds of L. occidentalis germinate to higher percentages in light. Stratified seeds germinate to higher percentages in dark.
Growing Area Preparation/
Annual Practices for Perennial Crops:

Greenhouse and outdoor nursery growing facility.
Sowing Method: Direct Seeding. Seeds are covered with medium and irrigated thoroughly.
Growing mediuma 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: Medium is kept slightly moist during germination. Germinants shed the seedcoats 7 to 10 days after emergence.Seedlings are thinned at this stage.
Length of Establishment Phase: 2 weeks
Active Growth Phase: Seedlings usually reach the accelerated growth stage 6 weeks after germination.
Plants were fertilized with 25-10-10 liquid NPK fertilizer during the growing season. Seedlings can be inoculated with ecto-mycorrhizal fungi at this stage. Plants were fully root tight 23 weeks after germination and averaged 10 cm in height.
Length of Active Growth Phase: 20 weeks
Hardening Phase: Trees are fertilized with 10-20-20 liquid NPK at 200 ppm from August to September. Irrigation is gradually reduced in September and October. Plants are leached with clear water before winterization.
Length of Hardening Phase: 4 weeks
Harvesting, Storage and Shipping: Total Time To Harvest: 6.5 months
Harvest Date: September
Storage Conditions: Overwinter in outdoor nursery under insulating foam cover and snow.
Length of Storage: 5 months
Outplanting performance on typical sites: Outplanting Site: Camas, Glacier National Park, MT.
Outplanting Date: Spring
Other Comments: Three L (1 gallon) containers can be produced in 2 years, with trees averaging 30 cm in height and 1.5 cm in caliper.
L. occidentalis hybridizes with L. lyallii where the elevation ranges of these species overlap.
Vegetative Propagation Method: Not tried. Softwood cuttings of juvenile stock plants of L. laricina, L. griffithii, and L. sibirica have been rooted with low percentages with 8000 ppm talc.
References: Flora of the Pacific Northwest, Hitchcock and Cronquist, 7th edition, University of Washington Press, 1973.

Seeds: Ecology, Biogeography, and Evolution of Dormancy and Germination, Baskin and Baskin, Academic Press, 1998.

The Reference Manual of Woody Plant Propagation, Dirr and Heuser, Varsity Press, 1987.

Seeds of Woody Plants in North America, Young and Young, Dioscorides Press, 1992.

Glacier National Park Native Plant Nursery Propagation Records, unpublished.

Luna, Tara; Evans, Jeff.; Hosokawa, Joy.; Wick, Dale. 2008. Propagation protocol for production of container Larix occidentalis Nutt. plants (172 ml conetainers); USDI NPS - Glacier National Park, West Glacier, Montana. In: Native Plant Network. URL: http://www.nativeplantnetwork.org (accessed 5 September 2015). Moscow (ID): University of Idaho, College of Natural Resources, Forest Research Nursery.

Protocol Information

Rae Watson
Forestry Technician
USDA FS - J Herbert Stone Nursery
2606 Old Stage Rd.
Central Point, Oregon 97537

Family Scientific Name: Pinaceae
Scientific Name: Larix occidentalis
Common Name: Western larch
Species Code: LAROCC
Propagation Goal: Plants
Propagation Method: Seed
Product Type: Bareroot (field grown)
Stock Type: 1+0
Time To Grow: 10 Months
Target Specifications: Minimum height of 4 inches and minimum caliper of 3mm.
Propagule Collection: Most seed comes from wild collections, with the remainder coming from seed orchards managed by the Forest Service and Bureau of Land Management. All seed is kept separate by the collection area, elevation and date collected. All seed is collected or contracted for collection by the Forest Service and Bureau of Land Management or other government agencies. All seed is collected in the fall.
Propagule Processing: Seed is sent to Bend Pine Extractory in the fall for cleaning. It is dried to between 5 and 8% moisture and placed in air tight plastic bags, then stored in seed freezers set at -15C (5F) at the nursery. This seed has a long storage life under these conditions.
Pre-Planting Treatments: Seed is placed in mesh bags and soaked in cold running water for 48 hour. The seed is then laid out 3cm (1 in) thick on trays with fine screen meshed bottoms and placed in cold stratification rooms for 30 to 45 days. Rooms are equipped with foggers to keep the naked seed moist at all times (seed covered with free moisture). Temperatures are set at 1C (33F). Seed is monitored daily to detect seed mold. If mold is found, the seed is hosed down with water.
Growing Area Preparation/
Annual Practices for Perennial Crops:

The climate of the Rogue Valley is dry, warm and sunny from late spring to early fall. High temperatures in the summer months average slightly below 32C (90F), with extremes occasionally over 40C (105F). Winters are cool and moist. January is the coldest month with an average daily temperature of 4C (39F). Valley fog is prevalent from mid November through late February, making condition for lifting seedlings very favorable. Annual precipitation is 45cm (18in), with over 80 percent of this falling as rain between October and April.
Establishment Phase: Seeds are the first to be sown at the nursery (mid-March). Seed is sown through a modified Oyjard seed drill. Seed is sown for an initial seedling density of 215 seedlings/m2 (20 seedlings/ft2). Attached to the front of the seed drill is a fertilizer bander. Depending on our soil analysis the bander places 500 kg/ha (450 lb/ac) of potassium sulfate (0-0-53) and 400 kg/ha (360 lb/ac) of ammonium phosphate (11-52-0) is placed at a depth in the soil of10cm (4in). The seed drill has been adapted by attaching 8 steel bands to the drum. The bands are 3cm (1¼ in) wide by 1cm (3/8in) deep and 15cm (6 in) apart. As it rolls in front of the seeder, the band creates a small impression for the seed to drop into. The tubes of the seed drill have been increased in size to allow large seed to pass through and drop directly into the impressions. Behind the seed tubes are small wheels that press the seed into the surface of the soil. Within a half hour of sowing, and then covered with 1cm to 1.3cm (3/8 to ½ in) of fresh (undecomposed) sawdust. The sawdust is sprayed with Agrilock at 15% solution to hold it in place in case of high winds. Then the seedbeds are sprayed with Goal (oxyfluorfen) at 2 pints per acre as a pre-emergent control for weeds.The seedbeds are irrigated when the seed appears to be drying out. This occurs only on warm days. There is no fertilization during this period.
Length of Establishment Phase: 4 weeks
Active Growth Phase: Irrigation: Soil tensiometers are placed at 15cm (6in) depths and monitored at least once per week. Soils are irrigate to 30cm (12in) when tensions are at -0.2 or higher. Light (5 minute) bursts of irrigation are given when surface soil temperatures (temperature probe placed under a ¼ inch of soil) are 33C (91F) in June; 35C (95F) in July; 38C (100F) in early August and 40C (104F) in mid August. Fertilizer: Fertilizer is applied in granular form over the seedlings. After application is complete, the fertilizer is washed off the foliage and into the soil with a half hour of irrigation water. Four applications are made: Approximately 6 weeks after emergence, 56 kg/ha (50 lbs/ac) of ammonium nitrate is applied when lateral roots have developed from new germinants. 8 weeks after emergence – 84 kg/ha (75 lbs/ac of ammonium nitrate. 10 weeks after emergence – 181 kg/ha (162 lbs/ac) ammonium sulfate, 12 weeks after emergence – 120 kg/ha (100 lbs/ac) of ammonium nitrate and 14 weeks after emergence – 120 kg/ha(100 lbs/ac) of ammonium nitrate.IPM: Handweeding of beds if necessary. If lygus insect found to damage buds, utilize mechanical insect control (Bug suck vacuum) and isecticide (Pydrin) at 10 day intervals until damage from insect no longer observed.
Length of Active Growth Phase: 4 months
Hardening Phase: By the third week in August or when the seedlings dormancy is induced.Irrigation: Only irrigate when the surface temperatures exceed 38C (100F) or pre-dawn plant moisture stress (PMS) exceeds 10 bars. In the early fall the soil profile is completely moistened and plants are kept below 5 bars pre-dawn PMS. From October through the early portion of November, the seedlings are protected from frosts through irrigation. Fertilizer: Two applications of112 kg/ha (100 lbs/ac) applied in mid-fall after bud set 2 weeks apart. IPM: Handweed beds if needed. Prunes and wrenches: No prunes or wrenches.
Length of Hardening Phase: 2 months
Harvesting, Storage and Shipping: Larch are the first seedlings to be lifted. Usually all larch are lifted between December 1 and December 15 of each year. Seedlings are hand-lifted after the seedlings beds have been undercut using an Lundeby lifter. Lifting conditions must be in unsaturated soils, PMS below 15 bars and temperatures above –3C (27F). Seedlings are stored at 1C (33F) and 100 percent humidity for 1 to 5 days before sorting. Sorting removes seedlings that do not meet target specifications (see above). Many clients ask for seedlings to be rootpruned between 23 and 30cm (9 and 12 inch) for planting reasons. We accomplish this with paper cutters. At clients request, we will place a rubber band around a group of seedlings, usually 25. Seedlings are placed in 3 ply bags and sown shut. The bags are placed on racks and stored in coolers at 1C (33F) for storage durations less than 2 months or in freezers at –1C (29F) for greater than 2 months.
Length of Storage: Up to 6 months
Other Comments: Larch is sensitive to manipulation of roots and increased salt levels. For this reason, surface salt levels are monitored and roots are not pruned or wrenched.
References: Schopmeyer C.S. 1974. Seeds of Woody Plants in the United States. Ag Handbook 450. USDA Forest Service.

Duryea M.L., Landis T.D. 1984. Forest Nursery Manual: Production of Bareroot Seedlings. Martius Nijhoff/Dr W. Junk Publishers, the Hague Boston/Lancaster, Forest Research Lab, OSU Corvallis. 386p.

Steinfeld, David E 2001. Propagation protocol for production of field-grown Larix occidentalis plants (1+0); USDA FS - J Herbert Stone Nursery, Central Point, Oregon. In: Native Plant Network. URL: http://www.nativeplantnetwork.org (accessed 5 September 2015). Moscow (ID): University of Idaho, College of Natural Resources, Forest Research Nursery.

Protocol Information

Carol and Jerry Baskin
University of Kentucky
University of Kentucky
Lexington, Kentucky 40506-0225

Family Scientific Name: Pinaceae
Family Common Name: Pine family
Scientific Name: Larix occidentalis Nuttall
Common Name: Western larch
Species Code: LAROCC
General Distribution: L. occidentalis is found from 500 to 1600 m elevation; from British Columbia south to Washington,Oregon, Idaho, and Montana.
Propagation Goal: Plants
Propagation Method: Seed
Product Type: Container (plug)
Propagule Processing: Seeds exhibit physiological dormancy.
Pre-Planting Treatments: Seeds are placed in cold moist stratification for 0 to 42 days. Germination occurs at 30D/20N C alternating temperature cycle.
Germination is greater in light than in dark.
References: Rudolf, P. O. (1974g). Larix Mill. Larch. Pp. 478-485. In: C. S. Schopmeyer (Tech. Coord.). Seeds of woody plants in the United States. USDA. Forest Service. Agriculture Handbook No. 450.
Baskin, C.J. and Baskin, J.M. Seeds: Ecology, Biogeography and Evolution in Dormancy and Germination, Academic Press, 1998. Chapter 10: A Geographical Perspective on Germination Ecology: Temperate and Arctic Zones, pages 331 to 458.

Baskin, Carol C.; Baskin, Jerry M. 2002. Propagation protocol for production of container Larix occidentalis Nuttall plants; University of Kentucky, Lexington, Kentucky. In: Native Plant Network. URL: http://www.nativeplantnetwork.org (accessed 5 September 2015). Moscow (ID): University of Idaho, College of Natural Resources, Forest Research Nursery.