Protocol Information

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

Family Scientific Name: Salicaceae

Family Common Name: Willow family

Scientific Name: Populus tremuloides Michx.

Common Name: Aspen

Species Code: POPTRE

Ecotype: Aspen Forest, Saint Mary, 1585 elev.

General Distribution: P. tremuloides occurs from Alaska to Labrador south to California, Arizona, and northern Mexico, through the Rocky Mountains to Texas, the Great Basin states, and from the Dakotas and Nebraska east across the upper Mid-West and south through New England to Virginia.

Propagation Goal: Plants

Propagation Method: Vegetative

Product Type: Container (plug)

Stock Type: 3 L containers

Time To Grow: 2 Years

Target Specifications: Stock Type: Container cuttings
Height: 30 cm
Caliper: 8 mm
Root System: firm plug in containers.

Propagule Collection: Vegetative Propagation Method: Pre-Rooting
Type of Cutting: Root cutting.

Propagule Processing: Lateral Roots 1 to 2.5 centimeters in diameter are collected from healthy clones in early June.
Suckering ability may vary considerably. It is best to take several root cuttings from many lateral roots from younger trees. Sections collected nearest the bole of the donor tree produce more shoots.

Pre-Planting Treatments: Roots are cut into 10 to 20 centimeter sections> The ends of each root cuttings are sealed with paraffin, and root cuttings are placed in a 2 minute Domain fungicide bath to kill surface pathogens.
Root sections are placed in a mist bed with bottom heat set at 21C until shoots emerge and are are 5 cm tall.
Shoots are excised with a razor blade from the root cuttings and treated with 2000 ppm IBA rooting hormone powder before sticking shoot cuttings in the mist bed with bottom heat setat 21C for 8 weeks until an adequate root system is generated.
Rooting %: 95% of excised shoots produce roots.

Growing Area Preparation/
Annual Practices for Perennial Crops:
The outdoor mistbed has automatic intermittent mist that is applied at 6 second intervals every 6 minutes. Too frequent misting will result in leaf and stem rot. Misting frequency is increased or decreased according to daily outdoor temperature and wind.
Bottom heat is maintained at 21C with heating cables buried 12 cm beneath rooting medium.
Rooting medium is 50% perlite and 50% sand. Mistbed is covered with shadecloth during rooting. After cuttings are potted, they are moved to an outdoor shadehouse for 4 weeks. They are later moved to full sun exposure in the outdoor nursery and 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: Cuttings that were pre rooted were lifted out of mistbed after adequate root systems were formed. Roots generate from the nodes below the surface of the rooting medium.

Length of Establishment Phase: 8 weeks

Active Growth Phase: After cuttings were lifted from the mistbed, they were potted into 3L containers.
Growing medium used is 6:1:1 milled spaghnum 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 5 grams of Osmocote and 2 grams of Micromax per conetainer. Cuttings were irrigated after potting and placed in the shadehouse for 4 weeks.
After establishment in the shadehouse, plants were moved to full sun exposure in the outdoor nursery.

Length of Active Growth Phase: 10 weeks

Hardening Phase: Containers are leached with clear water to remove excess salts prior to winterization of nursery stock.

Length of Hardening Phase: 4 weeks

Harvesting, Storage and Shipping: Total Time To Harvest: 2 years
Harvest Date: September of the second year.
Storage Conditions: Overwinter in outdoor nursery under insulating foam and snow.

Length of Storage: 5 months

Outplanting performance on typical sites: Outplanting Site: Lake McDonald, Glacier National Park, MT.
Outplanting Date: Spring or Fall
Outplanting Survival at 5 Years:100%
Outplanting Site: Saint Mary, Glacier National Park, MT.
Outplanting Date: Spring or Fall
Outplanting Survival at 4 Years: 0%

Other Comments: Aspen is easily propagated by seeds and root cuttings. Seed production is rare in the northern Rocky Mountains.
Root cuttings appeared to have better vigor than seed propagated material.

References: Flora of the Pacific Northwest, Hitchcock and Cronquist, University of Washington Press, 7th printing, 1973.
Seeds of the Woody Plants in North America, Young and Young, Dioscorides Press, 1992.
Seeds of the Woody Plants in the United States, Agriculture Handbook No. 450, U.S.F.S., Washington D.C., 1974.
Vegetative Propagation of Rocky Mountain Aspen, Schier, G., U.S.D.A. Forest Service General Technical Report INT-44, August 1978.
Glacier Park Native Plant Nursery Propagation Records, unpublished.
1996 Revegetation Monitoring Report, Glacier National Park, Asebrook, J., Lamb, B., and Funk, T., unpublished.

Citation:

Johnson, Kathy; Luna, Tara; Wick, Dale; Evans, Jeff. 2008. Propagation protocol for vegetative production of container Populus tremuloides Michx. plants (3 L containers); USDI NPS - Glacier National Park, West Glacier, Montana. In: Native Plant Network. URL: http://www.nativeplantnetwork.org (accessed 16 January 2009). Moscow (ID): University of Idaho, College of Natural Resources, Forest Research Nursery.

Family Scientific Name:	Salicaceae
Family Common Name:	Willow family
Scientific Name:	Populus tremuloides Michx.
Common Name:	Aspen
Species Code:	POPTRE
Ecotype:	Aspen Forest, Saint Mary, 1585 elev.
General Distribution:	P. tremuloides occurs from Alaska to Labrador south to California, Arizona, and northern Mexico, through the Rocky Mountains to Texas, the Great Basin states, and from the Dakotas and Nebraska east across the upper Mid-West and south through New England to Virginia.
Propagation Goal:	Plants
Propagation Method:	Vegetative
Product Type:	Container (plug)
Stock Type:	3 L containers
Time To Grow:	2 Years
Target Specifications:	Stock Type: Container cuttings Height: 30 cm Caliper: 8 mm Root System: firm plug in containers.
Propagule Collection:	Vegetative Propagation Method: Pre-Rooting Type of Cutting: Root cutting.
Propagule Processing:	Lateral Roots 1 to 2.5 centimeters in diameter are collected from healthy clones in early June. Suckering ability may vary considerably. It is best to take several root cuttings from many lateral roots from younger trees. Sections collected nearest the bole of the donor tree produce more shoots.
Pre-Planting Treatments:	Roots are cut into 10 to 20 centimeter sections> The ends of each root cuttings are sealed with paraffin, and root cuttings are placed in a 2 minute Domain fungicide bath to kill surface pathogens. Root sections are placed in a mist bed with bottom heat set at 21C until shoots emerge and are are 5 cm tall. Shoots are excised with a razor blade from the root cuttings and treated with 2000 ppm IBA rooting hormone powder before sticking shoot cuttings in the mist bed with bottom heat setat 21C for 8 weeks until an adequate root system is generated. Rooting %: 95% of excised shoots produce roots.
Growing Area Preparation/ Annual Practices for Perennial Crops:	The outdoor mistbed has automatic intermittent mist that is applied at 6 second intervals every 6 minutes. Too frequent misting will result in leaf and stem rot. Misting frequency is increased or decreased according to daily outdoor temperature and wind. Bottom heat is maintained at 21C with heating cables buried 12 cm beneath rooting medium. Rooting medium is 50% perlite and 50% sand. Mistbed is covered with shadecloth during rooting. After cuttings are potted, they are moved to an outdoor shadehouse for 4 weeks. They are later moved to full sun exposure in the outdoor nursery and 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:	Cuttings that were pre rooted were lifted out of mistbed after adequate root systems were formed. Roots generate from the nodes below the surface of the rooting medium.
Length of Establishment Phase:	8 weeks
Active Growth Phase:	After cuttings were lifted from the mistbed, they were potted into 3L containers. Growing medium used is 6:1:1 milled spaghnum 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 5 grams of Osmocote and 2 grams of Micromax per conetainer. Cuttings were irrigated after potting and placed in the shadehouse for 4 weeks. After establishment in the shadehouse, plants were moved to full sun exposure in the outdoor nursery.
Length of Active Growth Phase:	10 weeks
Hardening Phase:	Containers are leached with clear water to remove excess salts prior to winterization of nursery stock.
Length of Hardening Phase:	4 weeks
Harvesting, Storage and Shipping:	Total Time To Harvest: 2 years Harvest Date: September of the second year. Storage Conditions: Overwinter in outdoor nursery under insulating foam and snow.
Length of Storage:	5 months
Outplanting performance on typical sites:	Outplanting Site: Lake McDonald, Glacier National Park, MT. Outplanting Date: Spring or Fall Outplanting Survival at 5 Years:100% Outplanting Site: Saint Mary, Glacier National Park, MT. Outplanting Date: Spring or Fall Outplanting Survival at 4 Years: 0%
Other Comments:	Aspen is easily propagated by seeds and root cuttings. Seed production is rare in the northern Rocky Mountains. Root cuttings appeared to have better vigor than seed propagated material.
References:	Flora of the Pacific Northwest, Hitchcock and Cronquist, University of Washington Press, 7th printing, 1973. Seeds of the Woody Plants in North America, Young and Young, Dioscorides Press, 1992. Seeds of the Woody Plants in the United States, Agriculture Handbook No. 450, U.S.F.S., Washington D.C., 1974. Vegetative Propagation of Rocky Mountain Aspen, Schier, G., U.S.D.A. Forest Service General Technical Report INT-44, August 1978. Glacier Park Native Plant Nursery Propagation Records, unpublished. 1996 Revegetation Monitoring Report, Glacier National Park, Asebrook, J., Lamb, B., and Funk, T., unpublished.

Family Scientific Name:	Salicaceae
Family Common Name:	Willow family
Scientific Name:	Populus tremuloides (Michx.)
Common Name:	Quaking aspen
Species Code:	POPTRE
Ecotype:	Larimer county, CO 7500-8000' elevation.
General Distribution:	P. tremuloides is found from Alaska to Labrador,south to California, northern Mexico, Tennessee and New Jersery.
Propagation Goal:	Plants
Propagation Method:	Seed
Product Type:	Container (plug)
Stock Type:	1+0 container
Time To Grow:	5 Months
Target Specifications:	Height: 12 in. Caliper: 4 mm. Root System: Firm plug.
Propagule Collection:	Source of Seeds: Self-collected. Collection Date: Start looking in mid to late May, but check frequently because seeds develop and blow away within a few weeks.
Propagule Processing:	Seeds/Kg: 3,000,000%. Germination: 90%+. % Purity: Contains leaf chaff. Seed Processing: Collect branches with mature yet closed catkins. Put branches in water-filled large garbage cans in a warm enclosed room with little air movement. Within 5 days catkins will open releasing cotton in a controlled fashion. Vacuum up cotton. Separate seeds from cotton in center sieve between two additional standard testing sieves (total of three), middle sieve sized to permit seed passage. Sieve sizes top to bottom: Gilson #18 (1.00 mm), #35 (500 micrometer), #140 (106 micrometer). Gently blowing air from a reversed shop-vac through the sieves removes the seed from the cotton. Seed collects in bottom sieve. Seed storage: Store at -7 � C (20 � F) in sealed glass vial to eliminate drying. % Germination: 90%+
Pre-Planting Treatments:	None, usually collected in spring of year one, seed is sown spring of year two.
Growing Area Preparation/ Annual Practices for Perennial Crops:	Propagation Environment: Shadehouse. Container Type and Volume: Colorado Styroblock - 492 cm3 (30 in3). Growing Media: Scotts Forestry Mix.
Establishment Phase:	Sowing Date: Late May. % Emergence and Date: Germination within 24 hours, cotyledons within 48 rs. Sowing/Planting Technique: Manual sowing with salt shaker. Establishment Phase: Light misting twice a day until germination. Germination to two true leaf stage takes two weeks and seedlings are thinned to one per container at that time. Regular deep watering twice a week with complete fertigation solution based on 100 ppm nitrogen.
Length of Establishment Phase:	3 weeks
Active Growth Phase:	Late June to mid-August. Continue twice a week fertigation. Apply VA mycorrhizae beginning of phase. We use a product called BuRize from Buckman Laboratories.
Length of Active Growth Phase:	6 weeks
Hardening Phase:	In mid-August cease fertilizing, flush with clear water, reduce waterings until leaf drop in early October.
Length of Hardening Phase:	6 weeks
Harvesting, Storage and Shipping:	Total Time to Harvest: Seedlings can be grown to specifications in five months, stored overwinter in the shadehouse, and ready to ship the following spring Harvest Date: Seedlings can be graded after leaf drop in early October or prior to shipping the following spring. Storage Conditions: Outdoor shadehouse.
Length of Storage:	5 months
Outplanting performance on typical sites:	Outplanting Date: April to June Outplanting Site: Colorado
References:	Seed collection guide available at:http://www.colostate.edu/Depts/CSFS/Aspenseed.pdf

Family Scientific Name:

Salicaceae

Family Common Name:

Willow family

Scientific Name:

Populus tremuloides (Michx.)

Common Name:

Quaking aspen

Species Code:

POPTRE

Ecotype:

Larimer county, CO 7500-8000' elevation.

General Distribution:

P. tremuloides is found from Alaska to Labrador,south to California, northern Mexico, Tennessee and New Jersery.

Propagation Goal:

Plants

Propagation Method:

Seed

Product Type:

Container (plug)

Stock Type:

1+0 container

Time To Grow:

5 Months

Target Specifications:

Height: 12 in. Caliper: 4 mm. Root System: Firm plug.

Propagule Collection:

Source of Seeds: Self-collected.
Collection Date: Start looking in mid to late May, but check frequently because seeds develop and blow away within a few weeks.

Propagule Processing:

Seeds/Kg: 3,000,000%.
Germination: 90%+.
% Purity: Contains leaf chaff.
Seed Processing: Collect branches with mature yet closed catkins. Put branches in water-filled large garbage cans in a warm enclosed room with little air movement. Within 5 days catkins will open releasing cotton in a controlled fashion. Vacuum up cotton. Separate seeds from cotton in center sieve between two additional standard testing sieves (total of three), middle sieve sized to permit seed passage.
Sieve sizes top to bottom: Gilson #18 (1.00 mm), #35 (500 micrometer), #140 (106 micrometer).
Gently blowing air from a reversed shop-vac through the sieves removes the seed from the cotton. Seed collects in bottom sieve.
Seed storage: Store at -7 � C (20 � F) in sealed glass vial to eliminate drying.
% Germination: 90%+

Pre-Planting Treatments:

None, usually collected in spring of year one, seed is sown spring of year two.

Growing Area Preparation/
Annual Practices for Perennial Crops:

Propagation Environment: Shadehouse. Container Type and Volume: Colorado Styroblock - 492 cm3 (30 in3). Growing Media: Scotts Forestry Mix.

Establishment Phase:

Sowing Date: Late May.
% Emergence and Date: Germination within 24 hours, cotyledons within 48 rs.
Sowing/Planting Technique: Manual sowing with salt shaker.
Establishment Phase: Light misting twice a day until germination. Germination to two true leaf stage takes two weeks and seedlings are thinned to one per container at that time. Regular deep watering twice a week with complete fertigation solution based on 100 ppm nitrogen.

Length of Establishment Phase:

3 weeks

Active Growth Phase:

Late June to mid-August. Continue twice a week fertigation. Apply VA mycorrhizae beginning of phase. We use a product called BuRize from Buckman Laboratories.

Length of Active Growth Phase:

6 weeks

Hardening Phase:

In mid-August cease fertilizing, flush with clear water, reduce waterings until leaf drop in early October.

Length of Hardening Phase:

6 weeks

Harvesting, Storage and Shipping:

Total Time to Harvest: Seedlings can be grown to specifications in five months, stored overwinter in the shadehouse, and ready to ship the following spring
Harvest Date: Seedlings can be graded after leaf drop in early October or prior to shipping the following spring. Storage Conditions: Outdoor shadehouse.

Length of Storage:

5 months

Outplanting performance on typical sites:

Outplanting Date: April to June Outplanting Site: Colorado

References:

Seed collection guide available at:http://www.colostate.edu/Depts/CSFS/Aspenseed.pdf

Family Scientific Name:	Salicaceae
Family Common Name:	Willow family
Scientific Name:	Populus tremuloides (Michx.)
Common Name:	Quaking aspen
Species Code:	POPTRE
Ecotype:	Taos County (north-central), NM, 8000 ft. to 9500 ft. elevation.
General Distribution:	P. tremuloides is found from Alaska to Labrador, south to California, northern Mexico,Tennessee and New Jersery.
Propagation Goal:	Plants
Propagation Method:	Vegetative
Product Type:	Container (plug)
Target Specifications:	Height: 30 cm. Caliper: 3 mm. Root System: Firm plug.
Propagule Collection:	VEGETATIVE PROPAGATION: Root Cuttings. Rationale for Vegetative Propagation from Nursery Stock Plants: Seed of local ecotypes is not available. The propagation of clones native to the mine site is preferred. Stock plants have to be grown in a nursery because wild stands can not provide sufficient root cuttings and these stands are inaccessible during the winter months. Nursery Stock Plant Establishment: Root cuttings were collected in October from wild stands by wrenching suckers out of very rocky soils.
Propagule Processing:	Cuttings were stored at 4� C for at least 2 months and then planted horizontally in flats in the greenhouse. Individual plants were transplanted to tree bands (81 cubic inch) and finally to 5 gallon egg cans after one year. Stock plants were grown for an additional growing season in a pot-in-pot nursery system to moderate media temperature and facilitate root cutting harvest. Stock plants were fertilized with controlled release (17-6-12 plus minors, 3 to 4 month) fertilizer and top dressed with sulfur to counteract alkaline irrigation water. Stock plants were watered daily with micro-spray emitters. Large variability in survival and growth of ramets from different stock plants of the same clone can be expected because of a substantial stock plant effect. Superior clones had less variation in survival and growth due to stock plant effect than inferior clones.
Pre-Planting Treatments:	Root Cutting Collection from Stock Plants: Root cuttings were collected from stock plants during March. When cuttings were harvested within 2 cm of the periphery of the root ball, individual stock plants yielded from 22 to 36 cuttings per pot. Average caliper ranged from 4 to 6 mm, the average length ranged from 8 to 9 cm. Cuttings were harvested with a slant cut on the distal end and a perpendicular cut on the proximal end. Root cuttings were soaked in a Captan suspension (1:125 volumetric ratio, i.e., 2 tbs./gal) immediately after harvesting for 15 to 30 minutes, placed in polyethylene bags containing moist Spaghnum peat moss, and stored at 4� C for 6 to 12 weeks before planting. The growth of all tested aspen clones showed an overall trend with small caliper-long cuttings having the best growth and large caliper-short cuttings having the poorest growth. The overall survival trend for all clones indicates that the longer cuttings were superior. Long cuttings averaging 10 cm in length are preferable. Cutting caliper as small as 3 to 4 mm is not detrimental and in some cases may be beneficial.
Growing Area Preparation/ Annual Practices for Perennial Crops:	Greenhouse Propagation: Cuttings were stuck vertically in 164 ml Super Cell Cone-tainers. Media was 2 parts Sunshine� #1 mix to 1 part perlite with controlled release fertilizer 17-6-12 plus minors (3-4 months) added at a rate of 2 kg/cubic meter. Root cuttings were inserted into dibbled holes until the proximal end was just below the media surface. Ramets were fertilized once a week with 100 mg/l N from soluble fertilizer (20-10-20 plus minors).
Establishment Phase:	Eight weeks after sticking, 45 to 55 % of the ramets of the better growing clones had total stem lengths greater than 22 cm (9 inch).
Outplanting performance on typical sites:	Outplanting Site: High elevation revegetation of mine in Northern NM. Soils are overburden piles (high proportion of coarse fragments, volcanic origin), southerly aspects predominate Outplanting Date: Summer, during rainy periods in Late July and August
References:	Dreesen, D.R.; Harrington, J.T. 1998. Vegetative propagation of aspen, narrowleaf cottonwood, and riparian trees and shrubs. In: Landis, T.D., tech. coord. National Proceedings, Forest and Conservation Nursery Associations. Gen. Tech. Rep. SRS-25. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station: 129-137.

Family Scientific Name:

Salicaceae

Family Common Name:

Willow family

Scientific Name:

Populus tremuloides (Michx.)

Common Name:

Quaking aspen

Species Code:

POPTRE

Ecotype:

Taos County (north-central), NM, 8000 ft. to 9500 ft. elevation.

General Distribution:

P. tremuloides is found from Alaska to Labrador, south to California, northern Mexico,Tennessee and New Jersery.

Propagation Goal:

Plants

Propagation Method:

Vegetative

Product Type:

Container (plug)

Target Specifications:

Height: 30 cm. Caliper: 3 mm. Root System: Firm plug.

Propagule Collection:

VEGETATIVE PROPAGATION: Root Cuttings. Rationale for Vegetative Propagation from Nursery Stock Plants: Seed of local ecotypes is not available. The propagation of clones native to the mine site is preferred. Stock plants have to be grown in a nursery because wild stands can not provide sufficient root cuttings and these stands are inaccessible during the winter months. Nursery Stock Plant Establishment: Root cuttings were collected in October from wild stands by wrenching suckers out of very rocky soils.

Propagule Processing:

Cuttings were stored at 4� C for at least 2 months and then planted horizontally in flats in the greenhouse. Individual plants were transplanted to tree bands (81 cubic inch) and finally to 5 gallon egg cans after one year. Stock plants were grown for an additional growing season in a pot-in-pot nursery system to moderate media temperature and facilitate root cutting harvest. Stock plants were fertilized with controlled release (17-6-12 plus minors, 3 to 4 month) fertilizer and top dressed with sulfur to counteract alkaline irrigation water. Stock plants were watered daily with micro-spray emitters. Large variability in survival and growth of ramets from different stock plants of the same clone can be expected because of a substantial stock plant effect. Superior clones had less variation in survival and growth due to stock plant effect than inferior clones.

Pre-Planting Treatments:

Root Cutting Collection from Stock Plants: Root cuttings were collected from stock plants during March. When cuttings were harvested within 2 cm of the periphery of the root ball, individual stock plants yielded from 22 to 36 cuttings per pot. Average caliper ranged from 4 to 6 mm, the average length ranged from 8 to 9 cm. Cuttings were harvested with a slant cut on the distal end and a perpendicular cut on the proximal end. Root cuttings were soaked in a Captan suspension (1:125 volumetric ratio, i.e., 2 tbs./gal) immediately after harvesting for 15 to 30 minutes, placed in polyethylene bags containing moist Spaghnum peat moss, and stored at 4� C for 6 to 12 weeks before planting. The growth of all tested aspen clones showed an overall trend with small caliper-long cuttings having the best growth and large caliper-short cuttings having the poorest growth. The overall survival trend for all clones indicates that the longer cuttings were superior. Long cuttings averaging 10 cm in length are preferable. Cutting caliper as small as 3 to 4 mm is not detrimental and in some cases may be beneficial.

Growing Area Preparation/
Annual Practices for Perennial Crops:

Greenhouse Propagation: Cuttings were stuck vertically in 164 ml Super Cell Cone-tainers. Media was 2 parts Sunshine� #1 mix to 1 part perlite with controlled release fertilizer 17-6-12 plus minors (3-4 months) added at a rate of 2 kg/cubic meter. Root cuttings were inserted into dibbled holes until the proximal end was just below the media surface. Ramets were fertilized once a week with 100 mg/l N from soluble fertilizer (20-10-20 plus minors).

Establishment Phase:

Eight weeks after sticking, 45 to 55 % of the ramets of the better growing clones had total stem lengths greater than 22 cm (9 inch).

Outplanting performance on typical sites:

Outplanting Site: High elevation revegetation of mine in Northern NM. Soils are overburden piles (high proportion of coarse fragments, volcanic origin), southerly aspects predominate Outplanting Date: Summer, during rainy periods in Late July and August

References:

Dreesen, D.R.; Harrington, J.T. 1998. Vegetative propagation of aspen, narrowleaf cottonwood, and riparian trees and shrubs. In: Landis, T.D., tech. coord. National Proceedings, Forest and Conservation Nursery Associations. Gen. Tech. Rep. SRS-25. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station: 129-137.

Family Scientific Name:	Salicaceae
Family Common Name:	Willow Family
Scientific Name:	Populus tremuloides Michx.
Common Name:	Aspen
Species Code:	POPTRE
Ecotype:	Many Glacier, Glacier National Park, MT.
General Distribution:	P. tremuloide is found from Alaska to Labrador, south to California, New Mexico, Tennessee, and New Jersey.
Propagation Goal:	Plants
Propagation Method:	Seed
Product Type:	Container (plug)
Stock Type:	3 L Containers
Time To Grow:	2 Years
Target Specifications:	Stock Type: Container seedling Height: 45 cm Caliper: N/A Root System: Firm plug in 3L container.
Propagule Collection:	Seeds are collected during the first week of June at 1585 meters elevation. Catkin bearing branches are cut from female trees just before the capsules split open. Capsule color should be yellow at time of collection. Catkins are removed from branches and kept in a drying shed for 1 week until capsules open. Seeds are pulled from catkins and sown immediately. Mature seed color is tan.
Propagule Processing:	Seed Storage: 1 year at 0C. Aspen seeds are short lived and are sown immediately after collection. Seed dormancy is classified as nondormant. Seeds/Kg: 14,700,000/kg % Purity: N/A Germination: estimate 50 to 70% using fresh seed.
Pre-Planting Treatments:	None.
Growing Area Preparation/ Annual Practices for Perennial Crops:	Greenhouse and outdoor nursery growing facility. Sowing Method: Direct Seeding. Surface sow seed; needs light for germination. Sow several seeds per container to obtain 100% fill rate. Container Type and Volume: 172 ml conetainers. Growing medium used is 6:1:1 milled spaghnum 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. Seedlings are hand watered an remain in greenhouse until mid July. Seedlings are then moved to outdoor nursery for the remainder of the growing season.
Establishment Phase:	Germination begins 24 to 48 hours after sowing. Germination is uniform and is usually complete in 2 weeks. True leaves appear 2 weeks after germination. Seedlings are thinned at this stage.
Length of Establishment Phase:	3 weeks
Active Growth Phase:	Seedlings grow at a rapid rate after establishment. Plants are fertilized with 20-10-20 liquid NPK at 100 ppm during the growing season. Plants average 15 cm in height and 5 mm caliper in 4 months. The following spring, plants are uppotted into 3L ( 1 gallon) containers and are root tight at the end of the second growing season.
Length of Active Growth Phase:	16 weeks 1st year, 20 weeks 2nd year
Hardening Phase:	Plants are fertilized with 10-20-20 liquid NPK at 200 ppm in the fall, pots are leached with clear water, one final irrigation is applied before overwintering.
Length of Hardening Phase:	8 weeks
Harvesting, Storage and Shipping:	Total Time To Harvest: 2 years for 3L containers. 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: Many Glacier, Glacier National Park, MT. Outplanting Date: September.
Other Comments:	This speices is also propagated by root cuttings.
References:	Flora of the Pacific Northwest, Hitchcock and Cronquist, University of Washington Press, 7th printing, 1981. 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. Glacier Park Native Plant Nursery Propagation Records, unpublished.

Family Scientific Name:

Salicaceae

Family Common Name:

Willow Family

Scientific Name:

Populus tremuloides Michx.

Common Name:

Aspen

Species Code:

POPTRE

Ecotype:

Many Glacier, Glacier National Park, MT.

General Distribution:

P. tremuloide is found from Alaska to Labrador, south to California, New Mexico, Tennessee, and New Jersey.

Propagation Goal:

Plants

Propagation Method:

Seed

Product Type:

Container (plug)

Stock Type:

3 L Containers

Time To Grow:

2 Years

Target Specifications:

Stock Type: Container seedling
Height: 45 cm
Caliper: N/A Root System: Firm plug in 3L container.

Propagule Collection:

Seeds are collected during the first week of June at 1585 meters elevation. Catkin bearing branches are cut from female trees just before the capsules split open. Capsule color should be yellow at time of collection. Catkins are removed from branches and kept in a drying shed for 1 week until capsules open. Seeds are pulled from catkins and sown immediately. Mature seed color is tan.

Propagule Processing:

Seed Storage: 1 year at 0C. Aspen seeds are short lived and are sown immediately after collection.
Seed dormancy is classified as nondormant.
Seeds/Kg: 14,700,000/kg
% Purity: N/A
Germination: estimate 50 to 70% using fresh seed.

Pre-Planting Treatments:

None.

Growing Area Preparation/
Annual Practices for Perennial Crops:

Greenhouse and outdoor nursery growing facility.
Sowing Method: Direct Seeding. Surface sow seed; needs light for germination. Sow several seeds per container to obtain 100% fill rate.
Container Type and Volume: 172 ml conetainers.
Growing medium used is 6:1:1 milled spaghnum 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.
Seedlings are hand watered an remain in greenhouse until mid July. Seedlings are then moved to outdoor nursery for the remainder of the growing season.

Establishment Phase:

Germination begins 24 to 48 hours after sowing. Germination is uniform and is usually complete in 2 weeks. True leaves appear 2 weeks after germination.
Seedlings are thinned at this stage.

Length of Establishment Phase:

3 weeks

Active Growth Phase:

Seedlings grow at a rapid rate after establishment. Plants are fertilized with 20-10-20 liquid NPK at 100 ppm during the growing season.
Plants average 15 cm in height and 5 mm caliper in 4 months.
The following spring, plants are uppotted into 3L ( 1 gallon) containers and are root tight at the end of the second growing season.

Length of Active Growth Phase:

16 weeks 1st year, 20 weeks 2nd year

Hardening Phase:

Plants are fertilized with 10-20-20 liquid NPK at 200 ppm in the fall, pots are leached with clear water, one final irrigation is applied before overwintering.

Length of Hardening Phase:

8 weeks

Harvesting, Storage and Shipping:

Total Time To Harvest: 2 years for 3L containers.
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: Many Glacier, Glacier National Park, MT.
Outplanting Date: September.

Other Comments:

This speices is also propagated by root cuttings.

References:

Flora of the Pacific Northwest, Hitchcock and Cronquist, University of Washington Press, 7th printing, 1981.

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.

Glacier Park Native Plant Nursery Propagation Records, unpublished.

Family Scientific Name:	Salicaceae
Family Common Name:	Willow family
Scientific Name:	Populus tremuloides Michx.
Common Name:	Aspen
Species Code:	POPTRE
General Distribution:	P. tremuloides is found from Alaska to Labrador,south through the United States to Virginia and Nebraska, and south throughout the western states to northern Mexico.
Propagation Goal:	Plants
Propagation Method:	Seed
Product Type:	Container (plug)
Propagule Processing:	Seeds are non dormant. Germination occurs at 30D/20N C alternating temperature cycle.
References:	Zasada, J. C. and Viereck, L. A. (1975). The effect of temperature and stratification on germination in selected members of the Salicaceae in interior Alaska. Can. J. For. Res. 5, 333-337. Fechner, G. H., Burr, K. E. and Myers, J. F. (1981). Effects of storage, temperature, and moisture stress on seed germination and early seedling development of trembling aspen. Can. J. For. Res. 11, 718-722. 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.

Family Scientific Name:

Salicaceae

Family Common Name:

Willow family

Scientific Name:

Populus tremuloides Michx.

Common Name:

Aspen

Species Code:

POPTRE

General Distribution:

P. tremuloides is found from Alaska to Labrador,south through the United States to Virginia and Nebraska, and south throughout the western states to northern Mexico.

Propagation Goal:

Plants

Propagation Method:

Seed

Product Type:

Container (plug)

Propagule Processing:

Seeds are non dormant. Germination occurs at 30D/20N C alternating temperature cycle.

References:

Zasada, J. C. and Viereck, L. A. (1975). The effect of temperature and stratification on germination in selected members of the Salicaceae in interior Alaska. Can. J. For. Res. 5, 333-337.
Fechner, G. H., Burr, K. E. and Myers, J. F. (1981). Effects of storage, temperature, and moisture stress on seed germination and early seedling development of trembling aspen. Can. J. For. Res. 11, 718-722.
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.