Why does your Rhododendron ferrugineum have sudden leaf drop? Diagnose the cause and fix it with our step-by-step guide.
As an alpine species, Rhododendron ferrugineum requires consistent moisture but is highly sensitive to anaerobic conditions. Sudden leaf drop often occurs when the soil dries out completely during heatwaves or when heavy water saturation causes root hypoxia.
Oomycetes like Phytophthora thrive in poorly drained alpine soils. This pathogen attacks the fine feeder roots of the Alpine Rose, preventing water transport to the canopy and triggering rapid abscission.
While adapted to cold, sudden unseasonal heat spikes or rapid fluctuations in temperature can cause physiological stress. This triggers a defense mechanism where the plant sheds leaves to reduce transpiration surface area.
In acidic alpine soils, sudden leaf loss can follow a depletion of essential nutrients. While usually more gradual, a severe deficiency in magnesium can lead to chlorosis followed by premature leaf shedding.
Your plant might also be experiencing one of these issues:
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