Plants in USDA Hardiness Zone 2b need to be tough. The zone includes a bit of northern Minnesota and much of Alaska and Canada, with large parts of it forested, swampy or even permafrost. The average minimum temperature is -40 to -45 degrees Fahrenheit. Many of the habitats in Zone 2b are alpine, with high wind conditions and large snow covers.
The Lapland rhododendron (Rhododendron lapponicum) is a very low-growing evergreen shrub with clusters of bell-shaped, fragrant pink to lavender flowers. This dwarf shrub grows only about 2 inches tall, though it can reach 12 inches. This rhododendron, which is hardy to Zone 2b, is one of the first alpine species to flower. It grows in partial shade and prefers dry, alkaline soil.
Virginia creeper (Parthenocissus inserta) is a fast-growing tendriled, vined plant cold tolerant to Zone 1b. It has palmate leaves with five leaflets that turn purple to crimson in the autumn. Greenish-white, inconspicous flowers bloom in the summer. It tolerates any kind of soil, and will thrive even in full shade. It's tough and low-maintenance but does need some air movement to avoid powdery mildew.
Shrubby cinquefoil (Potentilla fruticosa) is a small, slightly spreading shrub that is hardy to Zone 2b. It has silky leaves that vary from dark green to blue green, depending on the cultivar. Its bright yellow flowers bloom from June through the first frost. Some cultivars have pink, orange or white flowers. It grows best in moist, well-drained soil, but is fairly adaptable. Shrubby cinquefoil will grow in partial shade.
Crowberry (Empetrum nigrum) is a perennial evergreen shrub that is hardy to Zone 2a. Its leaves are needlelike, growing on short branches in dense mats. It produces purplish crimson flowers in May and June. The juicy fruits are black and berrylike with white nutlets. You can eat crowberries, but they don't have much flavor. More than 40 species of birds count on crowberry for winter forage. It grows in partial shade and requires well-drained soil.