The Reasons and Solutions for Yellowing Leaves of Calla Lilies
As a popular ornamental plant, the yellowing of calla lily leaves has been troubling many gardening enthusiasts. Yellow leaves not only affect the plant's aesthetic value but also serve as a distress signal from the plant. This article will delve into the three main causes and provide step-by-step guidance on diagnosis and repair, allowing you to master the essentials of calla lily care.
I. Improper Water Management Causes Yellow Leaves
1.1 Dual Risks of Waterlogging and Drought
The calla lily's root system is extremely sensitive to water, and the soil moisture should be maintained at the golden range of 60%-70%. Water once every 2 days in summer and extend to 5-7 days in winter. It is recommended to use the bamboo skewer method to test: if soil particles stick to the skewer after removal, water is needed.
1.2 Scientific Rescue Plan
For yellowing leaves due to waterlogging, adopt the 'sandwich rescue method': place陶粒 at the bottom → replace with new soil → cover the surface with pine bark. For drought, use the immersion pot method to add water, keeping the water level at 1/3 of the pot height and soak for 20 minutes before immediate drainage.
II. Nutritional Imbalance Leads to Chlorosis
2.1 Unveiling Common Fertilizer Application Mistakes
In the growing season, a balanced ratio of nitrogen, phosphorus, and potassium (20-20-20) is needed, adjusted to a high-phosphorus formula (10-30-10) during flowering. Common mistakes include: using uncomposted organic fertilizer that burns roots, direct contact of solid fertilizer with roots, and continuous fertilization in winter.
2.2 Precise Fertilization Guide
Make 'calla lily nutrient water': mix banana peels + eggshells + rice washing water and ferment in a sealed container for 30 days, then dilute 50 times and use once every two weeks. When fertilizer damage occurs, rinse the roots with water three times in a row, followed by a 0.1% potassium permanganate disinfection.
III. Temperature Fluctuations Trigger Stress Responses
3.1 Key Points of Environmental Control
The ideal growth temperature range is 18-25°C, with a day-night temperature difference not exceeding 8°C. Use 'shade + water curtain' for double cooling in summer and a heating mat to maintain ground temperature in winter. Special attention should be paid to maintaining over 50% air humidity when caring for plants in air-conditioned rooms.
3.2 Emergency Temperature Measures
In case of high-temperature scorch, immediately move the plant to a north-facing balcony and wrap the pot with a damp cloth. After low-temperature frostbite, do not increase the temperature directly; instead, prune the necrotic tissue first and spray brassinolactone to promote recovery.
Through systematic analysis, it can be seen that the prevention and treatment of yellowing leaves in calla lilies require the establishment of a 'three-dimensional care system': keep a watering log to record soil moisture, create a fertilizing calendar, and set up an environmental monitor. It is recommended to perform a leaf microscopic examination monthly and use pH test paper to check the soil acidity (ideal value 6.0-6.5) to achieve a year-round green ornamental effect.