Phlox (speciosa)

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:	Polemoniaceae
Family Common Name:	Phlox
Scientific Name:	Phlox speciosa Pursh
Common Name:	showy phlox
Species Code:	PHSP
Ecotype:	Paradise Creek drainage near Pullman, Washington.
General Distribution:	Dry, open places in sagebrush steppe, grasslands, and open pine forests from southern British Columbia to northern California and east to Nevada and Montana.
Known Invasiveness:	not invasive
Propagation Goal:	plants
Propagation Method:	seed
ProductType:	Container (plug)
Stock Type:	10 cu. in.
Time To Grow:	4 Months
Target Specifications:	Tight root plug in container.
Propagule Collection:	Fruit is a capsule. The seed is dark brown in color and ripens in late June. Because the plants flower indeterminately and the capsules dehisce forcefully upon ripening, collecting seed is difficult and time-consuming. The seed must be collected as it ripens but before the capsules dehisce. Plants in seed increase plantings can be cut and dried under cover on tarps or in bags. Wild plants should never be collected whole. Small amounts can be dried in paper bags at room temperature with the top of the bag covered with open weave cloth. Larger amounts are dried on tarps in a greenhouse or shed. Plants are covered with garden row cover to prevent seed loss. Fans can be used to assure good air circulation. Stems and leaves are green at this point and mold will occur with poor air circulation.
Propagule Processing:	Most of theseed will shatter in the bag or on the tarp. Plant parts are discarded and the seed collected from the bottom of the bag or tarp. Very little seed is left in the inflorescence and recovering it is not worth the time and effort required. Small amounts are cleaned with an air column separator. Larger amounts are cleaned with air screen equipment. Clean seed is stored in controlled conditions at 40o Fahrenheit and 40% relative humidity.
Pre-Planting Treatments:	At least 90 days of cold moist stratification is required for adequate germination. Working with seed of another local ecotype, Nauman (2002) found 120 days of cold moist stratification in the dark resulted in the highest germination. She further noted seed is capable of germinating in cold temperatures. Fall seeding is recommended for another phlox, P. diffusa (Kingery et al 2003). Vegetative propagation is also possible (Kruckeberg 1996, Parish et al 1996). Unpublished data from trials conducted at the Pullman Plant Materials Center revealed that 5% emergence occurred without stratification. 45 days of cold, moist stratification resulted in 10% emergence. 90 days of cold, moist stratification resulted in 75% emergence. Increasing stratification time to 120 days resulted in 42% emergence. Seed planted in containers outdoors reached 55% emergence. Germination will occur at cold temperatures. Some seed will germinate during stratification and stratified seed will emerge more rapidly than untreated seed.
Growing Area Preparation/ Annual Practices for Perennial Crops:	In late October or early November seed is sown in 10 cu. in. Ray Leach Super cell conetainers filled with Sunshine #4 and covered lightly. A thin layer of coarse grit is applied to the top of the planting soil to prevent seeds from floating during watering. Conetainers are watered deeply and placed outside. Conetainers are moved to the greenhouse in January. Alternately, seed can be moist stratified in a refrigerator at 35-40o F for 90 days before sowing in the greenhouse.
Establishment Phase:	Medium is kept moist until germination occurs. Germination usually begins in 3 days and is nearly complete in 8 days, although a few seeds will continue to emerge up to 14 days later.
Length of Establishment Phase:	2 weeks
Active Growth Phase:	Plants are watered deeply every third day and fertilized once per week with a complete, water soluble fertilizer containing micro-nutrients. Plants may require water every other day during the final part of the active growth period.
Length of Active Growth Phase:	3-4 months
Hardening Phase:	Plants are moved to the cold frame in late March or early April, depending on weather conditions. They are watered every other day if the weather is cool, and every day during hot, dry spells.
Length of Hardening Phase:	2-4 weeks
Other Comments:	No insect problems have been noted. Plants are generally disease free although those growing in unusually wet spring weather conditions or moist microclimates are occassionally subject to powdery mildew. Plants continue to produce good seed crops in increase plantings for at least 5 years. Seed stored in controlled conditions at 40o Fahrenheit and 40% relative humidity retained high germination after 4 years.
References:	Daubenmire, R.F. 1970. Steppe Vegetation of Washington. Washington State Univ. Coop. Ext. Service EB 1446. Pullman, WA. Faust, Ralph and Peggy Faust. 1999. Wildflowers of the Inland Northwest. Museum of North Idaho. Coeur d'Alene, ID. 141 pp. Hitchcock, C. Leo, and Arthur Cronquist. 1973. Flora of the Pacific Northwest. University of Washington Press. Seattle, WA. 730 pp. Jolley, Russ. 1988. Wildflowers of the Columbia Gorge. Oregon Historical Society Press. Portland, OR. 332pp. Kruckeberg, Arthur R. 1996. Gardening with Native Plants of the Pacific Northwest. 2nd ed. University of Washington Press. Seattle, WA. 282 pp. Larrison, Earl J., Grace W. Patrick, William H. Baker, and James A. Yaich. 1974. Washington Wildflowers. The Seattle Audubon Society. Seattle, WA. 376 pp. Lyons, C.P. 1997. Wildflowers of Washington. Lone Pine Publishing, Renton, WA. 192 pp. Nauman, C. 2002. Germination of 12 Palouse Prairie forbs after stratification under light and dark treatments. M.S. Thesis, University of Idaho, Moscow ID. Parish, Roberta, Ray Coupe, and Dennis Lloyd (eds.). 1996. Plants of Southern Interior British Columbia. Lone Pine Publishing, Vancouver, BC, Canada. 463 pp. Piper, C.V., and R.K. Beattie. 1914. The Flora of Southeastern Washington and Adjacent Idaho. Lancaster, PA. Press of the New Era Printing Company. 296 p. Rickett, Harold W. 1973. Wildflowers of the United States: The Central Mountains and Plains. Vol. 6. (3 parts). McGraw Hill, New York. St. John, Harold. 1963. Flora of Southeastern Washington and of Adjacent Idaho. 3rd edition. Outdoor Pictures. Escondido, CA. 583 pp. Strickler, Dee. 1993. Wayside Wildflowers of the Pacific Northwest. The Flower Press, Columbia Falls, MT. 272 pp. Taylor, Ronald J. 1992. Sagebrush Country. Mountain Press Publishing Co. Missoula, MT. 211 pp. USDA ARS National Genetic Resources Program. Germplasm Resources Information Network - (GRIN) [Online Database]. National Germplasm Resources Laboratory, Beltsville, Maryland. URL: http://www.ars-grin.gov2/cgi-bin/npgs/html/taxon.pl?448068 (6 March 2008). USDA, NRCS. 2008. The PLANTS Database (http://plants.usda.gov, 6 March 2008). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.

Citation:

Skinner, David M,. 2008. Propagation protocol for production of Container (plug) Phlox speciosa Pursh plants 10 cu. in.; USDA NRCS - Pullman Plant Materials Center Pullman, Washington. 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.