A tough little plant that endures the frozen soils and brutal winters of the Arctic region's rocky barrens, tundra and taiga, tundra rosebay (Rhododendron lapponicum) is also called the Lapland rosebay. Holding onto its foliage through the winter, especially if it is nestled and protected under a blanket of snow, this shrub eventually breaks its dormancy to produce beautiful flowers around the summer solstice. This plant appreciates chilly but sunny surroundings in both winter and summer.
Tundra rosebay is considered a circumboreal plant, meaning it is native to regions that encircle the North Pole. Also called an "Arctic-alpine" plant, according to the University of Wisconsin, this shrub naturally exists in areas that resemble the tundra or high mountain altitudes in climate and soils. The native range of tundra rosebay includes Scandinavia (Lapland) and Russia, as well as Alaska, Canada and Greenland. In the United States, small pockets of the shrub occur in the Northeast and in Wisconsin, according to the Flora of North America database.
Usually low and prostrate with its stems, tundra rosebay can develop more upright branches if growing in a windless habitat or milder winter climate. It matures 6 to 12 inches tall and the shrub sprawls out to as much as 24 to 30 inches wide. Its underground roots form into fleshy roots called rhizomes. In early to midsummer, fragrant pink to violet-pink flowers can cover the entire plant, including the persistent leaves. After flowering the newest leaves unfurl and mature before the winter sets in.
Plant tundra rosebay in a very acidic soil (pH below 6.0) that is crumbly and well-draining, such as a sandy or gritty soil rich in organic matter like compost or peat. It needs abundant sunshine, at least eight hours daily. Top-dress the soil surface with organic matter such as decaying conifer tree needles each spring to provide nourishment to the plant during the short growing season when flowering and new leaves occur.
This shrub does not do well in regions with warm to hot summers and is best grown in montane regions, in a cool (chilled) greenhouse facility or alpine house or grown in the tundra or tiaga landscapes like a wildflower. Outdoors it is best grown where no more than two weeks of temperatures above 86 degrees F occur in summer, which correlates to American Horticultural Society heat-zones 1 or 2. Ample winter cold is necessary for flowering as well as long-term health of the plant, so it is best in U.S. Department of Agriculture winter hardiness zones 1 through 4.
Difficult to acquire and to grow in a garden setting, tundra rosebay does make an attractive ground cover among rocks or on a hillside among companion plants like heath, heather, cranberry and sphagnum moss. It may be grow in an alpine trough or other container if located in the appropriate climate. It makes a beautiful seasonal "wildflower" for rockeries on cold oceanside bluffs, mountain tops and high-elevation hiking paths.