The Rosa rugosa alba grows as a deciduous shrub that attains a height of approximately 6 feet with a 5-foot spread. From June to August the shrub rose is adorned with abundant white, fragrant blossom. Each blossom appears single, semi-double or double depending on the cultivar. The soft white flowers stand out against the bright crinkled foliage of the rose shrub. After blooming, large orange rose hips appear and stand out for fall and winter interest. They are often consumed raw or utilized in jams or jellies. The Rosa rugosa alba is a hardy, easy-to-grow shrub rose that has a place in virtually any landscape.
Choose a location with full sunlight or partial shade. Flower production is more abundant when the shrub is planted in full sunlight. Make sure the planting location will be able to accommodate the large size of the Rosa rugosa when fully grown. The shrub should have abundant air flow to its foliage to prevent disease such as black spot, powdery mildew and rust which grow on the rose bush when the foliage is allowed to remain moist without adequate airflow.
Ensure the area has well-draining soil. Mix in aged manure and abundant peat moss when planting the Rosa rugosa alba shrub. The soil should feel crumbly to the touch.
Dig a hole that is twice as large as the root system of the Rosa rugosa. Plant the shrub at the same level it was planted at the nursery. Firm soil over the rose bush's root system.
Apply 3 to 4 inches of mulch around the base of the Rosa rugosa. Use peat moss or bark chips. The mulch will help the soil stay moist, shade the shrub's roots in the heat of summer, offer wintertime protection and keep weed growth down.
Water the Rosa rugosa regularly. The shrub enjoys being kept moist and does not tolerate drought well. Avoid watering with overhead sprinklers. Use drip irrigation or a soaker hose to water the shrub. Overhead watering damages the flowers and promotes diseases.
Apply 3 to 4 inches of aged manure around the base of the Rosa rugosa every spring. Fertilize in the spring, summer and fall using a granular 5-10-5 fertilizer at a rate of 3 pounds per 1000 square feet.
Prune away a few flowers once they are spent to encourage repeat blooming. As the blooming season winds down allow a few flowers to stay on the shrub so the brilliantly colored hips are formed.
Mound soil and mulch 10 to 12 inches high around the base of the Rosa rugosa. The mound of soil will help insulate the plant during the winter months.
Prune the Rosa rugosa alba each spring by removing any dead or damaged canes. The shrub rose only requires moderate pruning and does not require severe pruning like a tea rose or a Floribunda rose.
Remove the mound of soil and mulch from the base of the Rosa rugosa in the spring when all danger of frost has passed. Simply smooth the soil and mulch into the flowerbed surrounding the shrub.