Populus (balsamifera)

Tara Luna USDI NPS - Glacier National Park West Glacier, Montana 59936 (406) 888-7835 http://plant-materials.nrcs.usda.gov/azpmc

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Family Scientific Name:	Salicaceae
Family Common Name:	Willow family
Scientific Name:	Populus balsamifera L. trichocarpa (T. & G.ex Hook.)
Common Synonym:	Populus trichocarpa
Common Name:	Black Cottonwood
Species Code:	POPTRI
Ecotype:	Lake Shore of Saint Mary, 4250' elevation.
General Distribution:	P. trichocarpa occurs from Alaska to Baja California, east to southwest Alberta, Montana, Wyoming and Utah. It is abundant in riparian forests and gravel bars along river and streams, montane and lower subalpine avalanche slopes and aspen groves.
Propagation Goal:	plants
Propagation Method:	vegetative
ProductType:	Container (plug)
Stock Type:	3 L containers
Time To Grow:	18 Months
Target Specifications:	Stock Type: Container cutting<br> Height: 25 cm<br> Caliper: 9 mm<br> Root System: firm plug in 3L (1 gallon) containers.
Propagule Collection:	Vegetative Propagation Method: Pre-Rooting Type of Cutting: Hardwood and softwood tip cuttings Hardwood cuttings: Late March, early April. Softwood cuttings: May, June, July.
Propagule Processing:	Cutting Treatments: Both hardwood and softwood cuttings are cut into 15 to 20 centimeter lengths with a caliper of 8 mm to 1.0 cm. Cuttings should not be taken from the part of the stem where maximum branching has occurred or from the tip portion of shoots were stored food is low and axillary bud development is incomplete.
Pre-Planting Treatments:	Cutting Treatments: Cuttings were cut into 15 to 20 cm lengths, with the base recut and 1/3 of leaves or buds removed. Cuttings were placed in a 2 minute fungicide bath to remove surface pathogens. Cuttings were treated with 1000 to 2000 ppm liquid IBA or none, and stuck in mist bed with at least 2 nodes below the surface of the rooting medium. High rooting percentages are easily obtained with both softwood and hardwood cuttings treated with 1000 to 2000 ppm IBA rooting hormone. Rooting %: 95 to 100%
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:	Time to Transplant: 8 weeks. Softwood cuttings were pre rooted and were lifted out of mistbed after adequate root systems were formed. Roots generate from the stem nodes below the surface of the rooting medium. Hardwood cuttings were directly stuck into 3 l (1 gal) containers filled with growing medium.
Length of Establishment Phase:	8 weeks
Active Growth Phase:	After softwood cuttings are rooted, they were potted into 3L containers. Both softwood and hardwood cuttings are planted in growing medium of 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 container. 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:	16 weeks
Hardening Phase:	Plants are fertilized with 10-20-20 liquid NPK at 200 ppm during August and September. Irrigation is gradually reduced in September and October. Plants were given one final irrigation prior to winterization.
Length of Hardening Phase:	4 weeks
Harvesting, Storage and Shipping:	Total Time to Harvest: 1.5 years. Cuttings rooted directly into 172 ml conetainers are root tight in 15 weeks. Harvest Date: September Storage Conditions: Overwinter in outdoor nursery under insulating foam and snow. One final irrigation is applied prior to overwintering.
Length of Storage:	5 months
Other Comments:	Black cottonwood is easily produced from cuttings and responds well to container culture. Regular fertilization and irrigation will yield 1.5 meter tall trees in 3 years. This species forms a symbiotic relationship with ecto-mycorrhizal fungi.
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. Glacier Park Native Plant Nursery Propagation Records, unpublished. Plant Propagation: Principles and Practices, 6th edition, Hartman, Kester, Davies,Jr. and Geneve, Prentice-Hall Press inc.,1997. 1996 Revegetation Monitoring Report, Glacier National Park, Asebrook, J., Lamb, B., and Funk, T., unpublished.

Citation:

Lapp, Joyce; Luna, Tara; Corey, Susan; Evans, Jeff; Wick, Dale; Hosokawa, Joy. 2008. Propagation protocol for production of Container (plug) Populus balsamifera L. plants 3 L containers; USDI NPS - Glacier National Park West Glacier, Montana. In: Native Plant Network. URL: https://NativePlantNetwork.org (accessed 2025/02/05). US Department of Agriculture, Forest Service, National Center for Reforestation, Nurseries, and Genetic Resources.