Canes on climbing roses grow vigorously, climbing along fences or other supports. These hardy plants prefer full sun and moist, nutrient-rich soil. In addition to the proper basic growing conditions, climbing roses may need some additional maintenance, including fertilising and pruning. Providing optimal growing conditions for climbing roses minimises the pruning needed by these plants.
Spring works best for pruning roses. Remove dead wood early in the spring to leave space for new canes. Climbing roses thrive with only light pruning to remove damaged areas. Other pruning should be done as necessary to maintain the desired shape. Prevent flower removal by waiting until after the first blooming period, unless the climbing rose is a cultivar that blooms only once. In that case, complete all pruning early in the season when the plant remains dormant. Climbing roses not given a trellis or other structure for support need heavier trimming to keep them under control. This will not harm the plant but leaves climbing roses looking more like a shrub with a vertical growth habit.
Pruning encourages new growth on plants. Done correctly, it also encourages new canes to grow in the desired direction, reinforcing the correct overall form. Prune after the first bloom to encourage the plant to produce more buds. Closely examine climbing roses while pruning to catch signs of disease or insect infestations early on, improving the chance of early treatment and survival. Flowers cut off during pruning work well in flower arrangements, as most climbing roses have large flower heads.
Always sharpen pruning shears before use. This ensures a clean cut, minimising damage to the canes. Prune vertical canes to increase the growth of lateral ones, where blooms appear. This increases the number of blooms. Cut lateral branches back to the fifth bud to encourage healthy growth and abundant blooming. Make cuts at a diagonal, and new canes will grow in the direction of the cut.
Tie long canes loosely to nearby supporting structures with string or gardening twine. This helps encourage growth in the desired direction, minimising the need for pruning. Avoid excessive fertilisation to reduce pruning requirements, as too much fertiliser results in significant foliage creation. Controlled fertilisation improves flowering, as the plant does not put all its energy into producing foliage. As a general rule, do not apply more than 1.36kg. per 1,000 sq. ft. of nitrogen fertiliser three times per growing season. Complete a soil test before fertilising to obtain accurate information on specific nutrient needs.