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The Forest Service National Center for Reforestation, Nurseries, and Genetic Resources (RNGR) is a leading source of technical information for nurseries and land managers regarding production and planting of trees and other native plants for reforestation, restoration, and conservation.

 
NPN Protocol Details Image

Penstemon (deustus)

Lee Riley
Horticulturist
USDA FS - Dorena Genetic Resource Center
34963 Shoreview Road
Cottage Grove, Oregon 97424
541-915-7324
541-767-5709 (fax)
leriley@fs.fed.us
Family Scientific Name: Scrophulariaceae
Family Common Name: Figwort
Scientific Name: Penstemon deustus
Common Name: Hot-rock penstemon
Species Code: PEDE4
Ecotype: Rogue River-Siskiyou National Forest, Oregon
General Distribution: Distribution: Hotrock penstemon is found in scattered populations in eastern Washington, southern Idaho, southwestern Montana and south through Oregon to the central Sierra Nevada in California, the northern portion of Nevada, northwestern Utah and western Wyoming.
Habitat: Hotrock penstemon inhabits dry rocky places, basalt flows, pressure ridges and cliffs and occasionally limestone outcrops in sagebrush, juniper and pinyon-juniper plant communities. Plants typically occur at elevations from 800 to 2500 m (2600 to 8200 feet).
Propagation Goal: Plants
Propagation Method: Seed
ProductType: Container (plug)
Stock Type: 164 ml (10 in3) container
Time To Grow: 17 weeks
Target Specifications: Stock Type: Container seedling Root System: Firm plug in container.
Propagule Collection: The white flowers bloom from May to July. Phenology varies based on elevation, aspect and seasonal weather patterns. The fruit (a capsule) is mature when it turns brown and begins to open. This typically occurs 5 to 8 weeks after flowering. Seed maturation is relatively uniform, and the brown to black seed persists in the capsules for several weeks. Seed capsules are collected by cutting mature inflorescences (racemes) with clippers and placing them into containers. The capsules are thoroughly dried and placed in a standard freezer for 48 hours to remove insect pests.
Propagule Processing: Penstemon deustus seed is very small (2,000,000-2,900,000/lb) compared to other seed in this genus and requires additional time for cleaning. Large stems are first removed by coarse sieving, and capsules are crushed on a rubbing board. Material is then passed through 1.7 and 1.18 mm sieves with square openings (Nos. 12 and 16 USA STS), followed by cleaning with a seed blower. Remaining debris is then separated by passing it through a No. 18 USA STS four more times until clean.
Pre-Planting Treatments: Due to small seed size, seeds are sown into trays filled with stabilized medium plugs (Q-plugs). A solution of 250 mg/L GA3 is poured over the cells to thoroughly moisten and seeds and cells. Trays are sealed inside plastic bags and placed into refrigeration at 1 to 3 °C for 60 days. Trays are checked weekly and kept moist throughout the stratification period. If mold is evident, trays should be treated with 1% hydrogen peroxide.
Growing Area Preparation/
Annual Practices for Perennial Crops:		 Q-plugs are lightly covered with nursery grit. Seedlings are transplanted to target containers approximately 3 weeks following removal from stratification.
Growing medium used is 40:20:20:20 peat:composted fir bark:perlite:pumice with Nutricote controlled release fertilizer (18N:6P2O5:8K2O with minors; 180-d release rate at 21C) at the rate of 0.8 gram Nutricote per 164 ml container.
Establishment Phase: Germination is not very uniform, depending on the quality of the seeds, and can take up to 3 weeks to be complete. Following germination (while still in Q-plugs), plants are fertilized with soluble 12-2-14-6Ca-3Mg at 75 to 100 ppm for 2 weeks.
Length of Establishment Phase: 3 weeks
Active Growth Phase: During the growing season, fertilization depends on weather and physiological needs. Soluble 20-9-20 NPK, 20-18-18 NPK, or 17-5-24 NPK at 100 to 150 ppm is applied weekly throughout the growing season.
Length of Active Growth Phase: 14 weeks
Hardening Phase: No dry-down is done to induce dormancy. Seedlings are moved to an outdoor growing area in mid-September.
Length of Hardening Phase: 2 to 3 weeks
Harvesting, Storage and Shipping: Harvest Date: Mid-October
Storage Conditions: Seedlings are usually outplanted in fall. No storage except in outdoor growing area. Plants are well irrigated prior to shipping and shipped in containers.
References: Dorena Genetic Resource Center Propagation Records, unpublished.

St. John L, Ogle DG, Shaw NL. 2003. Plant guide: Low beardtongue Penstemon deustus Douglas ex Lindl. Aberdeen (ID): USDA Natural Resources Conservation Service, Plant Materials Center. URL: https://plants.usda.gov/plantguide/pdf/cs_pede4.pdf (accessed 10 Oct 2018).

Parkinson H, DeBolt A. 2005. Propagation protocol for production of Container (plug) Penstemon deustus Dougl. plants USDA FS - Rocky Mountain Research Station Boise, Idaho. In: Native Plant Network. URL: http://NativePlantNetwork.org (accessed 2018/10/10). US Department of Agriculture, Forest Service, National Center for Reforestation, Nurseries, and Genetic Resources.

Citation:

Riley, Lee E.; Klocke, Allison. 2018. Propagation protocol for production of Container (plug) Penstemon deustus Plants 164 ml (10 in3) container; USDA FS - Dorena Genetic Resource Center Cottage Grove, Oregon. In: Native Plant Network. URL: https://NativePlantNetwork.org (accessed 2024/07/02). US Department of Agriculture, Forest Service, National Center for Reforestation, Nurseries, and Genetic Resources.