What to Do When the Middle of Red掌 Leaves Turns Black and Dries Up
Red掌 is favored for its brilliant spathe, but sudden black spots and drying in the center of the leaves often leave flower enthusiasts at a loss. This article will guide you through the causes of black spots on Red掌 leaves and targeted solutions with five core maintenance points.
One: Strategies for Dealing with Imbalanced Water Management
1.1 Identification of Waterlogging and Root Rot Symptoms
When the soil remains moist for more than three days, and the leaves develop central black spots along with softened stems, it indicates waterlogging root rot. Stop watering immediately and use bamboo sticks to create air holes in the potting soil.
1.2 Scientific Watering Plan
Switch to the immersion method for watering: place the pot in a water basin with 3 cm of water for 15 minutes, then remove and drain. Maintain a watering cycle of 7-10 days in spring and autumn, and extend it to 15-20 days in winter.
Two: Remedial Measures for Improper Fertilizer Application
2.1 Quick Diagnosis of Fertilizer Burn
Burnt edges of new leaves accompanied by radial black spots on old leaves are typical symptoms of fertilizer burn. Immediately rinse the potting soil with water three times and cut off leaves with more than 50% damage.
2.2 Precise Fertilization Plan
Choose a special liquid fertilizer with N-P-K=3-1-2 and use half the concentration as indicated on the instructions. Ensure the environment is well-ventilated within 24 hours after fertilizing and avoid water accumulation in the leaf center.
Three: Key Points of Environmental Control
3.1 Management During the Potting Adjustment Period
When leaf spots appear after repotting, maintain a stable temperature between 18-25°C. Use a transparent plastic bag to create a small greenhouse, and ventilate for two hours daily for seven days.
3.2 Control of Light Intensity
Use a 40% shade cloth to filter sunlight or place the plant on an east-facing windowsill. Avoid direct sunlight from 10:00 to 15:00 in summer, and allow soft direct light in winter.
Four: Comprehensive Control of Diseases and Pests
4.1 Process for Treating Leaf Spot Disease
When circular brown spots with a yellow halo are found, isolate the plant immediately. Alternate between spraying mancozeb (1:800) and carbendazim (1:1000) once a week for three weeks.
4.2 Pest Prevention Plan
Wipe the leaf backs with neem oil (5ml per liter of water) monthly to effectively prevent red spider mites. During the peak season for scale insects, sprinkle diatomaceous earth on the surface of the potting soil to form a protective layer.
By adjusting the watering rhythm, scientific fertilization, improving the lighting environment, and strengthening disease and pest control, the leaf spot problem of Red掌 can be effectively controlled. It is recommended to monitor the soil salt content with an EC value testing pen every quarter, maintain air humidity between 60%-70%, and allow Red掌 to continue to show a healthy appearance.