My Climbing Roses Are Not Blooming

With proper care, climbing roses can produce abundant blossoms.

Few flowering plants add beauty, color and fragrance along vertical supports quite like climbing roses do. Although climbing roses don't actually climb, proper support and pruning encourages their long canes to adhere to nearby structures, creating a vertical wall of blooming roses. Unfortunately, climbing roses may fail to bloom for a variety of reasons.

Sunlight

Climbing roses are members of the Rosaceae family of plants. Like most varieties of roses, climbing roses require full sunlight to produce abundant blooms. Although the plants may survive in shaded areas, insufficient amounts of sunlight can cause leggy growth and reduce the plant's ability to blossom. Planting climbing roses in areas that receive at least eight hours of sunlight a day will increase the chances of profuse flower formation. Cutting back overhanging branches and thinning out nearby tree canopies will help provide the necessary sunlight in areas with existing rose plants.

Pruning

Although flower formation varies in different cultivars, most climbing roses produce blossoms on both old and new growth. Heavy pruning in the winter can eliminate blossoms the following spring. Likewise, aggressive pruning during the spring can eliminate the segments of cane that contain new flower buds. Pruning lightly in the springtime or immediately after the blossoms fade helps eliminate overgrown canes without adversely affecting the rose's ability to flower.

Frosts

Late spring frosts are one of the major causes of failure to bloom in roses. Although many varieties of climbing roses go on to produce blossoms later in the summer, a hard frost after the buds form may eliminate the first wave of blooms. Protecting a leafed-out or budded climbing rose by covering it with a sheet prior to an expected frost can help save the young flowers and enable them to continue flowering as the weather warms.

Fertilizer

Climbing roses benefit from regular applications of fertilizer. However, using a fertilizer with a high nitrogen content tends to encourage foliage growth and discourage flower formation. A soil test is a helpful tool that can provide accurate information regarding the nutrient levels in the existing soil. During the early spring and summer, monthly applications of fertilizers labeled for use on flowering plants can help encourage flower buds to form on mature canes. Apply the fertilizer according to the package instructions. Too much fertilizer can burn the roots and damage the overall health of climbing roses.

References

• Colorado State University Extension; Climbing Roses; Becky Russell
• The Olympia Rose Society: Pests & Diseases
• Gardeners' World: Problem Solving
• "Botanica's Gardening Encyclopedia", Susan Page; 2001

Resources

• Washington State University Extension: Climbing Roses