GardenWizzPlant Care Card

Rhododendron calostrotum

Rhododendron calostrotum · Shrub

Hardiness

—

Position

Full sun, Partial shade

Height × Spread

— × —

Soil

acid soils with a pH of roughly 4.5–5.5; well-drained soils high in organic material

Flowering

April–May

Toxicity

poisonous to grazing animals because of a toxin called grayanotoxin in their pollen and nectar; extremely toxic to horses

The Gardening Year

🪴 Plant out

🌸 In flower

Powdery mildew: Improve air circulation and avoid overhead watering; tolerate mild infections or apply fungicide if severe.

Phytophthora root rot: Ensure well-drained acidic soil and avoid planting in heavy clay or frost pockets.

Vine weevil: Use nematode treatments in autumn or apply systemic insecticides to prevent root damage.

Bud blast: Remove and destroy infected buds promptly; ensure good ventilation and avoid late frosts.

Silver leaf: Prune out affected branches well below the infection site and burn debris to prevent spread.