Which Flowering Shrubs are Hardy to Zone Four?
Flowering shrubs add beauty to the landscape year-round, whether planted in grounds along a property boundary or around a home's foundation, or as specimen plants throughout the landscape. But not every shrub is hardy enough to survive the cold winters of USDA Hardiness Zone 4, which encompasses the northern US and higher elevations elsewhere in the country. Choose plants adapted to these cooler climates and you'll be rewarded with healthy foliage and lovely spring or summer flowers.
Arrowwood (Viburnum dentatum) produces clusters of white flowers in the spring, followed by bunches of blue berries in the summer and dark red foliage in the fall. Arrowwood can grow to be seven to 10 feet tall and does well in Zones 3 and 4.
The yellow, pea-like flowers of caragana (Caragana sp) bloom in profusion in summer and give the plant its other name of peashrub. Caragana averages three to five feet tall. The plants have dark green leaves and spiny stems. They are hardy in Zones 3 and 4.
The bright yellow flowers of forsythia appear in spring before the leaves on this popular landscaping shrub. Early forsythia (Forsythia ovata) is the variety best adapted to the cold winters of Zone 4.
Lilacs (Syringea sp) are among the most popular flowering shrubs for northern climates. The Minnesota Landscape Arboretum features almost 100 different varieties of lilacs in its collection, demonstrating the variety available. Lilacs bloom white, purple, lavender, maroon and almost every shade of blue or purple. Lilacs do well in Zone 4.
Mockorange (Philadelphus sp.) produce fragrant white flowers with a slight citrus of jasmine aroma. Mockorange prefer full sun. Most varieties do well in Zone 4.
Mountain Laurel (Kalmia latifolia) produces large clusters of very fragrant blossoms. If brought into the house, the grape-like fragrance of these blooms can be almost overpowering. The plant is hardy in Zone 4.
Northern Lights Azalea
Though azaleas are often thought of as southern plant, Northern Lights is bred for colder climates and is hardy in zones 3 and 4. Northern Lights was developed at the University of Minnesota. The blossoms are in shades of pink, from pale blush to a dark rose.