Developed by the University of Minnesota, the flower buds of these azaleas are hardy to -30° F. Enjoy their colorful blooms in late May and early June. An acid soil with a pH of 4.0 to 5.5 is essential for best growth. When planting we suggest spreading 1/2 lb. of fast acting Aluminum Sulphate around each plant, working it throughly into the soil. To maintain the proper pH a top dressing of 1 cup Soil Sulphur worked into the soil every 3 to 4 years is sufficient. Grow in full sun to part shade.