What to Do When Crinum Leaves Turn Yellow
Crinum, as a typical tropical ornamental plant, the issue of yellowing leaves has puzzled many growers. This phenomenon not only affects the ornamental value but may also endanger the plant's survival. This article systematically analyzes the causes of yellowing leaves from root care to environmental regulation, providing operational solutions.
Analysis of the Four Main Causes of Crinum Leaf Yellowing
Imbalance in Water Management
Excessive watering leads to soil waterlogging, impeding root respiration and causing rot, resulting in leaves turning yellow from the bottom up. It is recommended to use the bamboo skewer test: insert the skewer into the potting soil for 2 hours and pull it out; if no soil adheres to the tip, additional water is needed.
Abnormal Light and Temperature
Crinum thrives in a diffused light environment with temperatures between 15-25°C. Direct sunlight for more than 3 hours in summer can cause leaf tips to scorch, while temperatures below 10°C in winter can lead to inter-vein chlorosis. It is suggested to place the plant southward in spring and winter and move it to an east-facing windowsill in summer and autumn.
Disharmony in Nutrient Supply
During the growing season (April-September), a compound fertilizer (20-20-20) should be applied every 10 days, and additional phosphorus and potassium should be applied during the flowering period. Deficiency in nitrogen causes older leaves to turn yellow first, while iron deficiency leads to inter-vein chlorosis in new leaves.
Restricted Root Space
Not repotting for over 3 years can lead to root entanglement. It is recommended to use a new pot 5 cm wider in diameter during spring. When repotting, keep 1/3 of the original soil and mix in 30% perlite to improve aeration.
Systematic Treatment Plan
Emergency Response Procedure
Upon discovering yellow leaves, stop watering for 3 days → inspect the roots → trim the rotting roots (retain healthy white roots) → soak in carbendazim for 30 minutes → repot with new soil → cover with a bag to maintain humidity for 7 days.
Long-term Maintenance Strategy
Use the "moist when dry" watering method combined with using ceramsite as mulch, and monitor soil moisture with a soil moisture meter. Keep the substrate slightly dry in winter, and maintain air humidity above 60% by placing wet pebbles in a tray.
By systematically adjusting the maintenance methods, Crinum can usually recover in 2-3 months. It is recommended to wipe the leaves with diluted beer monthly, which not only removes dust but also supplements amino acids. Master these techniques to keep your Crinum lush and green all year round.