The Reasons and Solutions for the Yellowing of Cactus Leaves
Cacti, with their unique shapes, often puzzle caregivers with the phenomenon of yellowing leaves. This article systematically analyzes the three core causes and provides a scientific solution for cactus enthusiasts with practical illustrations.
I. Optimization of Soil Environment
Analysis of Soil Compaction Causes
Heavy clay soil is prone to form a compacted layer, hindering root respiration and nutrient absorption. When the soil pH value is greater than 7.5, calcium deposition accelerates compaction. Data shows that the breathability of compacted soil decreases by 60% compared to normal. It is recommended to test soil hardness monthly with a bamboo skewer, and if the insertion resistance is greater than 3N, it needs to be addressed promptly.
Four-Step Soil Improvement Method
Use the golden ratio of珍珠岩:蛭石:腐叶土=2:3:5, and add 5% bone meal to the potting mix to increase calcium and phosphorus content when repotting. After changing the soil, water control is required for 7 days, and watering should be gradually resumed after new roots sprout.
II. Construction of Water Management System
Quantified Watering Standards
In spring and autumn, follow the '333 principle': water every 3 weeks, penetrate 3cm of soil each time. Extend to 6 weeks during the summer high-temperature dormancy period, and completely stop watering in winter. Use a smart moisture meter to monitor, and only add water when the substrate moisture content is less than 15%.
Emergency Root Rot Treatment Process
Stop watering immediately when yellow leaves are found, disinfect the cutting tool with 75% alcohol, cut off the rotting roots, apply sulfur powder to the cut, place in a shaded area to air-dry the roots for 3-5 days, and then replant after callus formation.
III. Light Control Strategy
Light Intensity Demand Spectrum
Cacti require an average of 20000Lux of light for 6 hours a day, and the amount of chlorophyll synthesis decreases by 40% when light is insufficient. It is recommended to use full-spectrum plant lights for supplemental lighting, maintain a distance of 30cm from the light, and supplement light for 4 hours a day to effectively prevent yellowing.
Seasonal Light Management
Receive full sunlight in spring and autumn, shade 50% from 10:00 to 15:00 in summer, and use double-layer thermal insulation film to enhance light transmission in winter. Rotate the pot 180° every half month to ensure uniform light exposure.
IV. Comprehensive Maintenance System
Microenvironment Monitoring
It is recommended to set up a temperature and humidity recorder, keep the environmental humidity between 30-40%, and maintain the temperature between 15-28°C. Apply slow-release fertilizer every quarter, selecting a special formula with an NPK ratio of 5-10-5.
By establishing a three-dimensional maintenance model of soil, water, and light, combined with regular testing and dynamic adjustments, the yellowing issue of cacti leaves can be systematically solved. It is recommended to take growth comparison photos every quarter, establish a plant health record, and achieve precise maintenance.