What to Do When Viola Leaves Turn Yellow
As a widely popular indoor ornamental plant, the viola captivates many gardening enthusiasts with its elegant flower posture. However, during the maintenance process, it often encounters the issue of yellowing leaves, which seriously affects the plant's ornamental value. This article will systematically analyze the three main causes of yellowing leaves in violas and provide corresponding professional solutions to help you quickly restore the plant's healthy state.
Light Adjustment: The Key to Photosynthesis
Analysis of Yellowing Leaf Causes
Although violas can tolerate shade, long-term exposure to light intensity below 3000Lux hinders the synthesis of chlorophyll in the leaves, resulting in gradual yellowing. Especially in winter, when natural daylight hours are reduced to less than 5 hours, the probability of yellowing leaves increases by 60%.
Scientific Lighting Solutions
It is recommended to adopt a segmented lighting approach: 6 hours of scattered light per day in spring and autumn (avoiding the 10:00-14:00 intense light period), and extending to 8 hours in winter. Use a lux meter to measure and maintain the light intensity on the leaf surface between 5000-8000Lux. LED plant grow lights placed 40cm away from the plant are effective.
Water Management: The Core Element of Root Health
Irrigation Quantification Standards
Use the "Three-Finger Test": Insert the index, middle, and ring fingers 3cm deep into the potting soil; if 2/3 of the fingers are dry, it's time to water. 5-7 days/week in spring and autumn, 3 days/week (in the early morning) in summer, and extend to 10-12 days/week in winter. Each watering amount equals 15% of the pot volume, using a long-spout watering can to slowly pour along the pot walls.
Emergency Treatment Process
If yellowing leaves due to waterlogging are found, stop watering immediately, poke 5-8 ventilation holes in the potting soil with chopsticks, and place the plant in a well-ventilated area with a wind speed of 0.5m/s. For severe root rot, remove the plant from the pot, trim to retain healthy white roots longer than 3cm, soak in a 800x solution of carbendazim for 20 minutes, then replace with a new matrix of perlite:vermiculite = 3:1.
Nutrient Supply: Important Guarantee for Metabolic Balance
Fertilizer Ratio Solutions
In the growing season (March to October), apply N-P-K=20-20-20 water-soluble fertilizer every 15 days, strictly controlling the concentration between 800-1000 times. During the budding stage, apply additional potassium dihydrogen phosphate (1500 times solution), and stop fertilizing in winter. Pay special attention to supplementing magnesium, spraying 2000 times magnesium sulfate solution on the leaves monthly can prevent interveinal yellowing of old leaves.
Fertilizing Precautions
Adhere to the "Four No Principles": No fertilizing within 30 days of repotting, no fertilizing when the temperature is above 32°C, no fertilizing when the plant is wilted, and no fertilizing during full bloom. Organic fertilizer must be fully composted; recommend preparing a fertilizer solution with worm castings and water in a 1:10 ratio.
By systematically implementing the above three strategies of light regulation, precise watering, and scientific fertilization, the yellowing leaf issue in violas can usually be significantly improved within 2-3 weeks. It is recommended to complement this with a comprehensive monthly check-up: use a magnifying glass to inspect the undersides of leaves for pests, test the soil EC value (maintain between 0.8-1.2mS/cm), and promptly prune yellowed old leaves to promote the growth of new leaves. By mastering these key maintenance techniques, your viola will surely return to its healthy, glossy green state.