Shrubby cinquefoil is a deciduous shrub of alpine and subarctic regions across the Northern Hemisphere, widely sold under its former name Potentilla fruticosa. It produces five-petaled flowers from late spring through fall — yellow in the species, ranging to white, pink, and orange in cultivars — over a season that outlasts most flowering shrubs. Cold hardiness to zone 2a makes it a reliable choice where options are limited.
The plant is native to exposed mountain slopes and tundra margins, which explains its preference for lean, well-drained soils and its poor performance in rich or consistently moist ground. Those conditions encourage soft, rank growth and increase susceptibility to powdery mildew. Hard rejuvenation pruning every three to four years in early spring, cutting stems back close to the crown, keeps the plant compact and productive. It does not sucker and tolerates wind, road salt, and drought with minimal attention.
Leaves have been dried and steeped as tea — commonly called Kuril tea in Russia and Japan — a practice rooted in Siberian and East Asian folk medicine. Traditional preparations were used for digestive complaints and fever.
Powdery mildew
White or grey powdery coating on leaves — usually starting on older growth in humid conditions or when nights cool.
Improve air circulation by thinning plants. Apply neem oil or potassium bicarbonate spray at first sign. Avoid overhead watering.
Fungal leaf spot
Brown or purplish spots on the leaves, often ringed with a yellow halo, that spread and merge in warm, humid, or wet weather; heavily spotted leaves yellow and drop early.
Pick off spotted leaves and clear fallen debris to remove overwintering spores. Improve air circulation by thinning, and water at the base so foliage dries quickly. If it persists, apply a copper- or sulfur-based fungicide at the first sign.
Rust
Orange to brown raised pustules on the undersides of leaves, with yellow spotting on the upper surface. Heavy infections cause leaves to yellow and drop.
Remove and destroy infected leaves. Avoid overhead watering and improve air circulation. Apply a sulfur or copper-based fungicide if it spreads. Clear plant debris in fall.