Dotting the dry meadows, slopes, ridges and rocky tundra is the evergreen shrub known as the tundra rose bay. This plant is remarkably durable and tolerant of inhospitable growing conditions, surviving long winters and incessant cold winds. In the summertime, the cool soil and long days provoke a display of pretty pink flowers. Tundra rose bay is also called "Lapland rosebay," alluding to a boreal region of Scandinavia and its small green leaves.
The tundra rose bay is native across much of northern North America in the slightly alkaline soils in rock outcroppings across the northern highland mountains (up to 5,000 feet) or Arctic tundra. Isolated populations occur within the United States in Wisconsin, New York and Maine. According to the Flora of North America website, it also occurs in Arctic and sub-Arctic areas of Scandinavia, Russia and Siberia.
Even though called a "bay," this shrub is botanically classified in the genus Rhododendron. It is a member of the heath family, Ericaceae. It is closely related to blueberry, heather, mountain laurel and andromeda.
The U.S. Forest Service comments that tundra rose bay grows between 2 and 12 inches tall, typically in the shorter half of that generous growth height range. In protected spots where wind doesn't reach plants, the shrub can grow up to 24 inches tall when nestled among rocks. This prostrate shrub grows from rhizomes with many-branched woody stems. The leaves are typically persistent, although a lack of snow cover in the bitter winter months can cause some foliage to dry and drop away. The pinkish violet flowers are fragrant with five fused petals, occurring from late spring to midsummer (later if at a high elevation or latitude).
This cool-season shrub needs a sunny exposure, between six and 10 hours of sunlight in the growing season. It excels in a well-drained, moist, gravel to sandy soil that is coarse in texture but with some organic matter. Tundra rose bay needs a cool summer, with no more than 30 days that ever get above 86 degrees Fahrenheit (American Horticultural Society Heat-Zone 1 though 4). It also needs a pronounced, long and cold winter dormancy, such as those common in U.S. Department of Agriculture Hardiness Zones 1 through 5.
As a rhododendron species, no parts of the plant (especially leaves) should be eaten as they contain toxins like grayanotoxin and arbutin glucoside. Grazing livestock and rodents are equally at risk of poisoning if the leaves or flowers are consumed, according to The Rhody Man.