Gardening advice: Managing rose mildew and cultivating Cornus alba

Gardening advice focuses on managing powdery mildew in roses and cultivating Cornus alba (dogwood) for year-round ornamental value.

Powdery mildew is a fungal disease that thrives in warm days and cool, humid nights. It manifests as white-gray, flour-like spots on leaves, causing them to curl, yellow, and drop. To prevent spread, gardeners should avoid over-fertilizing with nitrogen, ensure adequate sunlight through proper spacing, and maintain regular watering at the roots. Infected plant parts should be removed and disposed of in mixed waste rather than compost to prevent overwintering.

Cornus alba, specifically the ‘Sibirica’ cultivar, is recommended as a hardy ornamental shrub or hedge. It is frost-resistant down to −40 °C and provides visual interest through its white flowers in spring, colorful autumn foliage, and bright red or wine-colored branches in winter. For optimal color, the shrub should be grown in sun or partial shade and pruned every two to three years in early spring to encourage new, brightly colored growth.