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Winter restoration at Metro's natural areas
Planning and conservation › Natural areas, parks and trails › Restoration › Restoration highlights › Winter restoration
Learn about restoration activities in Metro's natural areas that rely on winter's hibernation cycle to prepare for spring's warmth.
While you might think of spring as planting season, the late fall and winter months are prime planting time for the seeds, shrubs and trees so critical to ongoing restoration efforts at Metro's natural areas. More about Metro's restoration program
Bare root shrubs and trees, carefully chosen for historic habitat accuracy by Metro's science and stewardship team, arrive at the restoration site in a dormant state, ready to be planted in the cold ground where they will rest and recover until spring.
Seeds supplied by Metro's Native Plant Center depend on the frost and weathering action of the cold winter months to soften their hard coats. Known as stratification, this cold weather conditioning allows seed embryos to break through in the spring in search of warm sun and nutrients.
Winter 2009-2010 restoration projects
Graham Oaks natural area
During the winter of 2008, close to 150,000 native trees and shrubs common throughout the Willamette Valley in the 1800s were planted at Graham Oaks natural area in Wilsonville to restore historic landscapes and create rare wildlife habitat. The slow growing Oregon white oak planted as part of the restoration effort will need 50 to 100 years to transform open fields into oak savanna and woodland, making it a legacy project to be enjoyed by future generations. This winter, AmeriCorps crews staked 2,000 native wildflowers and sedges grown from seed gathered on Metro sites by staff and volunteers. Students from a neighborhood school placed young plants in plots they had adopted while contractors planted the rest of the area. The bamboo stakes serve as markers to protect the young plants from damage when the area is mowed.
Gales Creek floodplain
The 44-acre Gales Creek property, located in the Tualatin and Gales Creek watersheds just south of Forest Grove, provides a different challenge to restoration crews during the winter. Lying mostly within the Gales Creek floodplain, a large portion of the site floods each winter. Late summer mowing and fall spraying are the last maintenance activities at Gales Creek until the following spring. The wet winters make bank stabilization a priority. Planting the riparian buffer between creek and land with native plants and trees helps minimize erosive runoff, promote bank stability and support water quality. The Native Plant Center provides native grass and wildflower seeds collected locally for winter restoration efforts.