Clarkia (pulchella)

Dave Skinner PMC Farm Manager USDA NRCS - Pullman Plant Materials Center Room 211A Hulbert Hall WSU Pullman, Washington 99164-6211 509-335-9689 509-335-2940 (fax) abbie@wsu.edu http://plant-materials.nrcs.usda.gov/wapmc

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Family Scientific Name:	Onagraceae
Family Common Name:	Evening Primrose
Scientific Name:	Clarkia pulchella Pursh
Common Name:	Elkhorn clarkia, Ragged robin
Species Code:	CLPU
Ecotype:	Paradise Creek drainage, Pullman, WA.
General Distribution:	Northwestern US east to South Dakota. Usually found on south slopes in dry, open grassland and open Ponderosa pine forest.
Propagation Goal:	plants
Propagation Method:	seed
ProductType:	Container (plug)
Time To Grow:	3 Months
Target Specifications:	Tight root plug in container
Propagule Collection:	Wild seeds are collected when the caspules begin to split. Plants in seed increase plantings are cut and dried in paper bags at room temperature. The plant flowers and matures seed indeterminantely, thus a judgement must be made as to when to cut the plants to maximize seed production. Seeds are small and dark brown in color. We determined 2,090,323 seeds/lb for this ecotype.
Propagule Processing:	For small amounts, capsules are crushed and seed separated with a hand screen. Fine material is removed with an air column separator. Larger volumns are threshed with a hammermill and cleaned with air screen equipment. Seed is stored at 40 degrees Fahrenheit and 40% relative humidity after cleaning.
Pre-Planting Treatments:	None required. There may be an after-ripening requirement. Seed lots have been observed to germinate at higher rates after storage in cold, dry conditions. 30 days cold, moist stratification did not enhance germination in trials conducted at the PMC.
Growing Area Preparation/ Annual Practices for Perennial Crops:	In February, seeds are sown in 10 cu. in. Ray Leach Supercell conetainers filled with Sunshine #4. Seeds are covered lightly with media. A thin layer of pea gravel is applied to prevent seeds and media from floating. Conetainers are watered deeply. Using planting soils with slower drainage has been observed to increase diseases of this species in the Plant Materials Center greenhouse.
Establishment Phase:	Medium is kept moist until germination occurs. Germination usually occurs in 5-7 days and is complete in 10-12 days.
Length of Establishment Phase:	2 weeks
Active Growth Phase:	Plants are watered deeply every other day and fertilized once per week with a water soluble, complete fertilizer containing micronutrients.
Length of Active Growth Phase:	2 months
Hardening Phase:	Plants are moved to the cold frame in late March or early April, depending on weather conditions. Exposure to direct sunlight and cool temperatures is increased over a period of two weeks. Plants may begin flowering by this time.
Length of Hardening Phase:	2-4 weeks
Other Comments:	This is an annual species. It reseeds itself well if there are openings in the vegetative cover where it can become established. Preliminary results from direct seeding trials in the field suggest that seed sown in the fall establishes at a high rate. Seed field sown in the spring failed to germinate.
References:	Hitchcock, C. Leo, and Arthur Cronquist. 1973. Flora of the Pacific Northwest. University of Washington Press. Seattle, WA. St. John, Harold. 1963. Flora of Southeastern Washington and of Adjacent Idaho. 3rdedition. Outdoor Pictures. Escondido, CA. USDA, NRCS. 2004. The PLANTS Database, Version 3.5 (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 70874-4490 USA. Young and Young. 1986. Collecting, Processing and Germinating Seeds of Wildland Plants. Timber Press. Portland, OR.

Citation:

Skinner, David M,. 2004. Propagation protocol for production of Container (plug) Clarkia pulchella Pursh plants USDA NRCS - Pullman Plant Materials Center Pullman, Washington. In: Native Plant Network. URL: https://NativePlantNetwork.org (accessed 2025/04/25). US Department of Agriculture, Forest Service, National Center for Reforestation, Nurseries, and Genetic Resources.