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U.S. Forest Service

Choosing the Right Plant Materials

Consideration of the origin and genetic diversity of planting stock can be one of the most important decisions in a restoration project.

Seed zones and plant movement guidelines are used to help determine which plant materials would be best adapted to the climate and environment of a particular planting site.

Developing seed zones is a slow process, involving the measurement and analysis of plant traits over several years in a common garden study. Seed zones have been developed for many important forest tree species, but guidelines are generally lacking for other native species, especially grasses and forbs.

In the western regions of the Forest Service, where climates and environments tend to be extremely variable, research studies are underway to develop seed zones for a number of important restoration species, including mountain brome, bluebunch wheatgrass, prairie junegrass, Indian ricegrass, lupine, and others.

For additional information, see:

In the absence of seed zones derived from studies of adaptive genetic variation, provisional seed zones for native plants have been developed based on climate data.

Seed Zone Mapper

The Seed Zone Mapper is a new mapping application that allows end-users to easily view and download data on provisional seed zones for use in plant material development and gene conservation and restoration activities. Species-specific seed zones from common garden studies are also available. The Seed Zone Mapper contains a rich collection of background maps and ancillary layers (boundaries, etc.) in addition to the seed zone layers. More seed zones will be added as they become available.

Refer to the Threat and Resource Mapping (TRM) Applications, which includes Seed Zone Mapping.

man looking at rows of blue wildrye in a nursery. Common garden field plots of blue wildrye from northeastern Oregon and southeastern Washington (USA). Information from the study was used to develop the seed zones shown in the map to the right.

A seed zone map for the area around Walla Walla, Washington; and Pendleton and Baker City, Oregon. Seed zone map of blue wildrye (Elymus glaucus) in northeastern Oregon and southeastern Washington (USA). From "Landscape patterns of phenotypic variation and population structuring in a selfing grass, Elymus glaucus (blue wildrye)" (PDF, 532 KB)

Other Sources of Information