The Reasons and Solutions for Viola Yellow Leaves
Violas are favored by horticulture enthusiasts for their elegant flower posture, but yellowing leaves often plague growers during maintenance. This article systematically analyzes the four main causes of yellow leaves and provides professional solutions to help you restore the plant's fresh green vitality.
Four Main Causes and Countermeasures for Viola Yellow Leaves
1. Poor Ventilation Leading to Yellow Leaves
Poor air circulation is the primary issue in indoor maintenance. When the environmental humidity is >70% and continuously humid and hot, the plant will show symptoms of leaf edge scorching and overall yellowing. It is recommended to use a circulating fan to assist with ventilation, maintaining an air velocity of 0.3-0.5m/s, combined with opening windows for air exchange in the morning and evening, keeping the carbon dioxide concentration at 400-600ppm.
2. Light Imbalance Causing Yellow Leaf Syndrome
Violas should follow the principle of full sun in spring and autumn, 50% shading in summer, and supplementary lighting in winter. When the light intensity is <2000lux for more than 3 weeks, chlorophyll synthesis is hindered, leading to yellowing. Use a lux meter to monitor, and adopt a combination of a southeast-facing windowsill and supplementary lights to ensure an average daily light duration of 6-8 hours.
3. Improper Water Management
Over-frequent watering causes root hypoxia and rot, manifested as dark yellow new leaves and wilted old leaves. It is recommended to use a pottery pot and perlite matrix (proportion 1:3), check the soil moisture before watering, and water thoroughly when a bamboo stick inserted 3cm does not feel damp. Extend the interval to 10-15 days per time in winter.
4. Imbalance in Nutrient Supply
During the growing season (March-September), apply N-P-K=10-20-20 water-soluble fertilizer every 14 days, controlling the concentration at 800-1000 times liquid. Symptoms of nutrient deficiency yellowing leaves: nitrogen deficiency causes whole leaf yellowing, iron deficiency causes interveinal chlorosis in new leaves. It is recommended to correct with foliar application of chelated iron (0.05% concentration).
By regularly rotating the pot, cleaning the leaf surface stomata, and maintaining a day-night temperature difference of 8-10°C, yellowing can be effectively prevented from recurring. Mastering these scientific maintenance tips, the viola will surely reward your careful care with lustrous green leaves.