Why does your Hydrangea macrophylla Magical Blossom have yellow leaves? Diagnose the cause and fix it with our step-by-step guide.
In Hydrangea macrophylla, yellowing between the veins (interveinal chlorosis) while veins remain green is a classic sign of iron deficiency, often caused by high soil pH preventing uptake. This is particularly common in alkaline soils where iron becomes chemically unavailable to the plant.
Excessive moisture in the substrate leads to anaerobic conditions, causing root rot which prevents the hydrangea from transporting nutrients. This typically manifests as uniform yellowing of older leaves followed by wilting despite moist soil.
A lack of nitrogen causes the entire leaf to turn a pale yellow, starting with the older, bottom leaves. This is common in 'Magical' series hydrangeas if they are planted in depleted soil or have not been fertilized during the active growing season.
While primarily characterized by spots, severe fungal infections can cause localized chlorosis and eventual leaf yellowing. This occurs when high humidity or wet foliage provides the perfect environment for fungal spores to germinate.
Your plant might also be experiencing one of these issues:
English
Italiano
