What Causes the Yellowing of Lily Leaves
Lilies, as elegant ornamental plants, often encounter the issue of yellowing leaves during cultivation. This article systematically analyzes the four main causes of yellowing in lily leaves and provides corresponding solutions, allowing you to revitalize your lilies through scientific care.
Ⅰ. Issues Related to Impaired Root Respiration
1.1 Yellowing Leaves Caused by Overwatering
Lily bulbs have the characteristic of storing water, and a continuously moist environment can lead to root suffocation. It is recommended to use the finger joint detection method: insert the index finger into the second joint of the soil, and water when it is dry. Maintain a watering cycle of 7-10 days in spring and autumn, and shorten it to 5-7 days during high summer temperatures.
1.2 Soil Compaction Treatment Plan
Compacted soil can create a physical hypoxia environment. It is suggested to add 30% perlite and 20% decomposed leaf soil to the growing medium during potting every year. For daily maintenance, loosen the soil once a month with a gardening rake, keeping the depth between 5-8cm to avoid root damage.
Ⅱ. Nutritional Imbalance Issues
2.1 Scientific Fertilizing Schedule
In the germination stage (March-April), apply balanced slow-release nitrogen-phosphorus-potassium fertilizer; during the bud formation stage (May-June), add more monopotassium phosphate (800 times dilution); and after flowering (July-August), apply potassium fertilizer to promote bulb expansion. Pay attention to applying thin fertilizers frequently, keeping the concentration below 0.2%.
Ⅲ. Biological Invasion Issues
3.1 Comprehensive Control of Diseases and Pests
For piercing-sucking insects such as aphids and red spiders, you can use a 25% imidacloprid 2000 times dilution spray. To prevent root rot disease, it is recommended to soak the bulbs in a 500 times dilution of carbendazim for 20 minutes before planting. Regularly prune the bottom old leaves to maintain ventilation and light.
By accurately diagnosing the causes of yellowing leaves and taking targeted maintenance measures, combined with proper light, temperature, and humidity control, you can effectively restore the healthy state of lilies. It is recommended to establish a maintenance log to record watering, fertilizing, and pest and disease situations, gradually mastering the growth patterns of the plants.