Western Spiraea, Spiraea douglasii

Range

Alaska to California, east to Idaho.

Climate, elevation

Moist areas to water-logged soils (peat), full sun. Reportedly shade intolerant. Sea level to 6000 feet

Local occurrence (where, how common)

Commonly distributed in Western Washington in low to mid-elevations.

Habitat preferences

Moist areas, swamps, lake margins and damp meadows, sea level to subalpine. Coniferous forests.

Ben Legler

Plant strategy type/successional stage (stress-tolerator, competitor, weedy/colonizer, seral, late successional)

It can be invasive, crowding out other native plants, especially in wetland areas. Occurs mostly in seral communities. Pioneer species in clearcut areas.

Associated species

Juncus ensifolius, Carex vesicaria, C. sitchensis, C. obnupta, Epilobium glandulosum, Angelica genuflexa, Equisetum arvense, Veratrum californicum, Alnus viridis ssp. sinuata, Lonicera involucrata, Cornus sericea, Vaccinium caespitosum, Elymus glaucus, Blechnum spicant, Pteridium aquilinum, Achillea millefolium, Carex eurycarpa, Rosa woodsii, and Ribes lacustre.

May be collected as: (seed, layered, divisions, etc.)

Seed, hardwood and softwood cuttings, divisions. 

Collection restrictions or guidelines

Bag seedheads to capture ripening seed. Allow pods to dry on plant; break open to collect seeds. Collect seed in the fall.

Seed germination (needs dormancy breaking?)

Fresh seed germinates easily without any pretreatment while dry seed may require one to two months of cold stratification. Seeds should be soaked for 24 hours before stratification in mesh bags in peat.

Seed life (can be stored, short shelf-life, long shelf-life)

Can be stored for at least one year.

Propagation recommendations (plant seeds, vegetative parts, cuttings, etc.)

Can be grown from seed, softwood hardwood cuttings, root cuttings, or division. Responds well to bottom watering.

Soil or medium requirements (inoculum necessary?)

100 percent peat.

Installation form (form, potential for successful outcomes, cost)

Rooted plants to 6' tall in containers; bareroot & cuttings 18"-24" tall

Recommended planting density

Plants 3+ feet on center, cuttings 2+ feet on center.

Care requirements after installed (water weekly, water once etc.)

Requires consistently moist soil; do not let dry out between waterings.

Normal rate of growth or spread; lifespan

Fast growing, to 3-6 feet tall and spreads easily, forming monocultures. Short-lived, less than 50 years.

Sources cited

Hudson, Shelley and Michael Carlson. Propagation of Interior British Columbia Native Plants from Seed. http://www.for.gov.bc.ca/HFD/Pubs/Docs/Mr/Mr093/Mr093.pdf

Washington State Dept. of Ecology. 1993. Restoring Wetlands in Washington: A Guidebook for Wetland Restoration, Planning and Implementation.

Rose, Robin et al. 1998. Propagation of Pacific Northwest native plants. Corvallis : Oregon State University Press

AllRefer.com Reference: http://reference.allrefer.com/

Burke Museum Herbarium: http://www.washington.edu/burkemuseum/collections/herbarium/index.php

The Theodore Payne Foundation California Native Plant Library http://www.theodorepayne.org/gallery/glossary.htm

WSU Master Gardener Native Plant Guide: http://gardening.wsu.edu/nwnative/

Washington State Dept. of Ecology: Controlling Erosion Using Vegetation. http://www.ecy.wa.gov/programs/sea/pubs/93-30/index.html

Dave’s Garden: http://davesgarden.com

WACD Plant Materials Center: http://www.kccd.net/Roy_Bach_Plant_Sale/Plant_Guide.pdf

King County: Role and Use of Vegetation: http://dnr.metrokc.gov/wlr/biostabl/PDF/9305BnkStbCh6.pdf

National Tree Seed Laboratory: USDA Forest Service: http://www.nsl.fs.fed.us/

Data compiled by:

Lorraine Brooks

April 27, 2006