Hibiscus leaves turn yellow primarily due to common issues like improper watering (either overwatering or underwatering), nutrient deficiencies (such as nitrogen or iron), inadequate or excessive sunlight, temperature stress (too hot or too cold), pest infestations, root-bound conditions, or natural dormancy in colder seasons. Each of these factors disrupts the plant’s ability to maintain healthy, green leaves, resulting in yellowing as a stress signal.
Main Causes of Yellow Hibiscus Leaves
- Watering Problems: Overwatering can cause root rot, leading to yellow, soft, and wilted leaves, while underwatering results in dry, crisp yellow leaves and wilting.
- Light Exposure: Hibiscus needs bright light; too much direct sun can cause yellowing and sun damage, while too little light results in yellow and dropping leaves.
- Nutrient Deficiencies: Lack of nitrogen causes older leaves to yellow as it’s needed for chlorophyll production, and iron deficiency leads to yellow leaves with green veins (chlorosis).
- Temperature Stress: Hibiscus prefers warm temperatures (65-85°F); exposure to frost or excessive heat can cause yellow leaves.
- Pests: Aphids, spider mites, whiteflies, and other pests can sap the plant, causing yellowing leaves.
- Root Issues: Being root-bound in pots limits nutrient and water uptake, causing yellow leaves.
- Dormancy: In cold seasons, some hibiscus varieties naturally yellow leaves as they enter dormancy.
How to Fix Yellow Leaves
- Adjust watering to keep soil moist but not soggy; water only when the top soil is dry.
- Provide partial shade during hot afternoons, but ensure adequate bright light.
- Fertilize regularly with balanced fertilizer (e.g., 20-20-20) in growing seasons and consider chelated iron if chlorosis occurs.
- Treat for pests with neem oil or appropriate insecticides.
- Repot if root-bound to allow root growth.
- Recognize dormancy as natural in cold climates, no intervention needed.
These care adjustments generally help restore hibiscus leaf health and prevent yellowing.
