How to Prevent Dahlia Leaves from Turning Yellow and Falling Off
Dahlias are stars in the garden with their colorful blooms, but yellowing and falling leaves often trouble dahlia enthusiasts. This not only affects their ornamental value but also serves as a health alert from the plant. This article systematically analyzes five key points of care, from soil basics to daily maintenance.
Basic Elements of Dahlia Cultivation
Scientific Potting Soil Mixture
Use a golden ratio of humus soil: perlite: coarse sand = 5:3:2, changing the soil every two years. Lay a 3cm layer of ceramsite at the bottom of the pot to prevent waterlogging and root rot while ensuring nutrient reserve.
Light Intensity Gradient Control
In the seedling stage, accept 50% shade net filtered light, and ensure 6 hours of diffused light per day for mature plants. From 11:00 to 15:00 in summer, set up a shade shelter to prevent leaf burn.
Refined Maintenance Management
Intelligent Water and Fertilizer Control Method
In spring and autumn, use the 'finger test method': when two finger joints inserted into the soil are dry, water thoroughly. Supplement with Meileke flower nutrient solution (diluted 1200 times) once a week, and add potassium dihydrogen phosphate during the budding stage.
Disease Prevention System
Rotate spraying with Mancozeb (800 times liquid) and Tebuconazole (1500 times liquid) monthly. Immediately cut off any diseased leaves and apply carbendazim powder to the cut surface to isolate pathogens.
Environmental Control Techniques
Maintaining a day-night temperature difference of 8-10°C is beneficial for nutrient accumulation; move the plant indoors if the nighttime temperature drops below 5°C. Keep the air humidity around 60%, which can be achieved by placing wet pebbles in a tray for local humidity increase.
By improving the cultivation matrix, optimizing light, water, and fertilizer, and establishing a preventive plant protection system, along with regular plant health checks, dahlias can maintain lustrous green leaves. Remember to remove the old basal leaves promptly to promote ventilation; your dahlias will certainly bloom more beautifully.