Magnolia grandiflora · Tree
Horse chestnut scale: Scrape off heavy infestations or spray with horticultural oil during the dormant season.
Coral spot: Prune out affected wood in dry weather and improve air circulation around the plant.
Phytophthora root rot: Ensure well-drained soil and avoid overwatering; remove severely infected plants.
Capsid bug damage: Monitor for pests in spring and treat with insecticidal soap if populations are high.
Grey mould: Remove infected material immediately and ensure good air circulation to reduce humidity.