Sandberg bluegrass (Poa secunda)

*This article was originally published in the Phlox Phlyer, the newsletter of the the Columbia Basin Chapter of the Washington Native Plant Society.

Sandberg bluegrass is a member of the Poaceae family and one of the first bunchgrasses to green up in the spring. This small cool-season native grass (generally <10 inches in our area) is widely distributed both in the State and in the western US. The leaves have the typical bluegrass characteristics of prow-shaped tip and double groove down the center of the leaf surface.  Plants of the Sandberg bluegrass complex have extensive, deep penetrating, coarse, fibrous roots that make them drought tolerant. 

The Sandberg bluegrass complex has included up to 45 named species including eight species recognized by Hitchcock (1935): Canby’s bluegrass (P. canbyi), big bluegrass(P. ampla), little mountain bluegrass (P. curtifolia), Pacific bluegrass (P. gracillima), alkali bluegrass (P. juncifolia), Nevada bluegrass (P. nevadensis), Pine bluegrass (P.scabrella),and the traditional Sandberg bluegrass (P. sandbergii). Presently only P. curtifolia is considered a separate species. The source of this confusion is that Sandberg bluegrass produces seed both sexually and asexually. While it appears the grass normally reproduces asexually, it outcrosses often enough to create new variations that are uniform not only morphologically but ecologically. Thus we have Sandberg bluegrass growing from 6 to 48 inches tall and found in all but 5 of Washington counties from sea level to alpine areas.

Sandberg bluegrass also apparently is habitat for the rare woven-spore lichen (Texosporium sancti-jacobi). This lichen depends on organic matter as a substrate and, as referenced by Halvorson, mainly grows on dead clumps of P. secunda, along with small animal dung.

Sandberg bluegrass occurs in open sun to partial shade, and is not harmed by fire or grazing. Also since it starts growing in the fall after the rains start it can compete with some of the exotic annuals.  From a forage standpoint it ranks among the most important grasses for wildlife and livestock.  Seeds are available from many of the native plant nurseries; see the Heritage Garden's Plant Material Providers page for a list of nurseries.

References: Halvorson, Ron, 2011. Sandberg Bluegrass (Poa secunda). Kalmiopsis 18:10-15; Burke Museum of Natural History and Culture Herbarium Site and the USDA PLANTS DatabasePhotos used with permission..