The roots of acid-loving plants are often sensitive to high nutrient concentrations.
Gentle, organic fertilizers such as the Cuxin fertilizer for rhododendrons, azaleas and ericas are highly recommended here.
Ingredients: 5% nitrogen, 6% phosphate, 8% potassium, 3% magnesium, 1% iron, organic matter 45%
Content: 750g in a resealable bag