Rose Care, Planting, and Common Pests
Roses are essential in a cottage garden or a traditional English border, but caring for roses can seem daunting to new gardeners.
The first step to caring for roses is choosing the right rose for your gardening style.
Climbing roses grow 8-12’ tall, require support and will have multiple flushes per season.
English roses were created by David Austin and have the disease resistance and fragrance of old roses combined with the repeat flowering and colour range of modern roses.
Floribunda roses is a modern rose that carries large clusters of flowers, often fragrant, and grows shrubbier than its modern rose counHterparts. Many disease resistant varieties are available.
Hybrid Tea and Grandiflora roses are both modern roses. Hybrid Teas provide intense fragrance and the traditional single rose on each stem. Grandiflora roses has the tall stature of Hybrid Teas, and the flower clusters of Floribundas. These modern roses are superior in colour and fragrance. Disease resistance and vigour varies by variety.
Landscape Roses vary from groundcovers to large shrubs. They often have excellent disease resistance and good repeat flowering.
Rugosa Roses are one of the hardiest and most disease resistant roses. These are large shrubs and need lots of space, but have great appeal with healthy foliage and rosehips.
Choosing Where to Plant Your Rose
Roses do best with a minimum of 6-8 hours of sunlight, good airflow, and humus-rich well-drained soil. Be sure to plant your rose where it has enough room to grow. When roses are congested they are more prone to diseases and fungal issues.
Top Rose Care Tips
Mulch around roses in the spring to prevent overwintering disease spores on the ground from being splashed onto plants and infecting leaves.
Avoid overhead irrigation and watering. Plant roses in full sun and prune to allow good air circulation so leaves can dry.
Prune roses to encourage good airflow.
Choose disease resistant varieties.
Common Pests and Issues:
Black spot (Diplocarpon rosae)
Round black spots appear on the leaves of roses and the edges of the spots can have a yellow halo around the spot. Black spot overwinters on infected leaves or canes of infected plants. Spores are carried by splashing rain, and wet weather favours the spread of the disease.
Control: In the fall prune infected roses within 4-6 inches of the graft to remove overwintering spores from cane tissue. Remove infected leaves and prunings, and rake up infected leaves throughout the season. Do not compost. Lime-sulphur can be sprayed to kill overwintering spores on dormant roses. Sulphur sprays can be used throughout the season but will need to be re-applied to prevent spores from infecting new foliage as it develops, generally every 7-10 days.
Powdery mildew (Podosphaera pannosa)
Very common on many garden plants, powdery mildew is a white, powdery fungus growth on young leaves and shoots. Powdering mildewcan overwinter on plant parts and debris. Germination of the fruiting structures occurs with warm, wet weather. Plants in shade are significantly more susceptible.
Control: There are many spray options available for powdery mildew and Linda Gilkeson’s book ‘West Coast Gardening: Natural Insect, Weed & Disease Control’ is a great resource. Sulphur sprays can be used as new leaves are unfurling. Physically remove infected growth.
Rust (Phragmidium)
Powdery orange or black spot appear on the underside of the leaves. Corresponding yellow spots appear on the upper leaf surface.Typical symptoms include general yellowing of leaves and curled or distorted stems. Rust often first appears on lower leaves. Mild temperatures and high moisture are favourable conditions for rust to develop.
Control: Low levels of infection can do little harm, so physical removal of infected leaves and stems is ideal. Lime-sulphur can be sprayed to kill overwintering spores on dormant roses. Sulphur sprays can be used throughout the season but will need to be re-applied to prevent spores from infecting new foliage as it develops, generally every 7-10 days.
Aphids
Aphids suck the plant sap out of tender young stems, leaves, and buds. They can cause distorted growth and affect flowering. Generally, aphids will not cause enough harm to be a concern. Use a strong spray of water to dislodge aphids from rose plants. Only apply nitrogen fertilizer when absolutely necessary to avoid excessive lush growth that the aphids are attracted to. Using an insecticide will kill natural predators so only do this when absolutely necessary.
Thrips
Thrips are very tiny insects that use rasping mouthparts to rip open cells and suck out juices that leak out. Difficult to detect in roses because thrips hide at the base of flower petals within buds. Their damage causes buds not to open or flowers are distorted when they open. Timely removal of spent or badly infested blooms may help reduce the thrips population. The best way to prevent thrips is to control weeds in and near your roses, as thrips feed on a variety of host plants including weeds. Pyrethrins can be used when damage is unacceptable but it is important to thoroughly coat the plants.
With proper care, roses can be a beautiful and fragrant addition to any garden.