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Penstemon (confertus)

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

Family Scientific Name: Scrophulariaceae
Family Common Name: Figwort family
Scientific Name: Penstemon confertus Dougl. ex Lindley
Common Name: Yellow penstemon
Species Code: PENCON
Ecotype: Fescue grassland 1100m elev. Big Prairie,
General Distribution: P. confertus occurs from valleys to the subalpine zone; throughout the Pacific Northwest east of the Cascades.It is found in B.C. and Alberta, south to Montana, Idaho, and Oregon.
P. confertus is a mat forming species that frequently colonizes road shoulders, cliffs, and disturbed ground in moist to dry meadows and prairies.
Propagation Goal: plants
Propagation Method: seed
ProductType: Container (plug)
Stock Type: 172 ml conetainers
Time To Grow: 8 Months
Target Specifications: Stock Type: Container seedling.<br> Height: 5 cm, 6 to 10 true leaves.<br> Caliper: n/a<br> Root System: Firm plug in container.
Propagule Collection: Seeds are collected in late summer when capsules turn brown and begin to dehisce. Seeds are brown at maturity. Capsules are collected in paper bags and kept in a well ventilated drying shed prior to cleaning.
Propagule Processing: Seeds are cleaned with an air screen cleaner by NRCS.
Seed longevity is at least 5 years at 1 to 3C in sealed containers.
Seed dormancy is classified as physiological dormancy.
Seeds/Kg: 4,600,000/kg.
% Purity: 100%
% Germination: 90 to 100%
Pre-Planting Treatments: 90 to 120 day cold, moist stratification.
Germination occurs in late spring under fluctuating temperatures in outdoor nursery. Germination occurred at 21C/15C (day/night) tempertures in the greenhouse.
Growing Area Preparation/
Annual Practices for Perennial Crops:
Outdoor nursery growing facility or Greenhouse.
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.
Conetainers are filled and sown in late fall and irrigated thoroughly prior to winter stratification.
Seedlings germinate in spring under fluctuating outdoor temperatures and are grown under full sun exposure. 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: Seedlings that were fall sown and stratified outdoors emerge in late spring. Germination was very uniform under fluctuating temperatures. True leaves appeared 2 weeks after germination. Once established and thinned after emergence, the seedlings produce rapid shoot and root development. Germination was also very uniform under greenhouse conditions. Cotyledons emerged 5 days after sowing.
Length of Establishment Phase: 3 weeks
Active Growth Phase: Plants are fertilized with 20-20-20 liquid NPK at 100 ppm during the active growth phase. Plants were root tight 9 weeks following germination. Plants did not produce flowers the first year.
Length of Active Growth Phase: 9 weeks
Hardening Phase: Plants are fertilized with 10-20-20 liquid NPK at 200 ppm in fall, pots are leached with water, and irrigation frequency is gradually reduced in September and October. One final irrigation is applied before covering for the winter.
Length of Hardening Phase: 4 weeks
Harvesting, Storage and Shipping: Total Time to Harvest: 8 months
Harvest Date: September
Storage Conditions: Overwinter in outdoor nursery under insulating foam and snow cover.
Length of Storage: 5 months
Other Comments: Vegetative Propagation Method: Divisions of established nursery stock can be done if seeds are unavailable.
References: Flora of the Pacific Northwest, Hitchcock and Cronquist, Univ. of Washington Press, 7th printing, 1973.
Glacier Park Native Plant Nursery Propagation Records, unpublished.
Seed Germination Theory and Practice, 2nd Edition, Deno, Norman, publ. 1993.
Seeds: Ecology, Biogeography and Evolution of Dormancy and Germination, Baskin and Baskin, Academic Press,1998.
Seeding Rate Statistics for Native Plants, Hassel, W. NRCS AND NPS, April 1996.


Luna, Tara; Evans, Jeff; Wick, Dale. 2008. Propagation protocol for production of Container (plug) Penstemon confertus Dougl. ex Lindley plants 172 ml conetainers; USDI NPS - Glacier National Park West Glacier, Montana. In: Native Plant Network. URL: http://NativePlantNetwork.org (accessed 2019/12/06). US Department of Agriculture, Forest Service, National Center for Reforestation, Nurseries, and Genetic Resources.

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