Reasons and Solutions for Osmanthus Yellow Leaves
Osmanthus, as a traditional famous flower, its golden leaves are often given a beautiful meaning. When yellow leaves are found in osmanthus, it often means that there is a problem in the maintenance process. This article focuses on three typical causes of yellow leaves, combined with 20 years of gardening experience to summarize a systematic solution.
Root Waterlogging: Invisible Fatal Injury
Although osmanthus prefers a humid environment, its fleshy roots are extremely sensitive to waterlogging. According to experimental data from Nanjing Forestry University, when the soil moisture content of potted osmanthus exceeds 40% for 3 consecutive days, the root damage rate reaches 67%. When identifying the characteristics of waterlogging, it is necessary to pay attention to the uniform yellowing of the leaves, accompanied by the phenomenon of new leaves wilting.
Light Stress: Photophyll Crisis in Leaves
In full sunlight, when the intensity of ultraviolet rays exceeds 50000lux in summer, the cuticle of osmanthus leaves will suffer irreversible damage. It is recommended to use a shading net to control sunlight, maintaining a range of 30000-45000lux. Observations show that leaves受损 by strong light burns usually show edge yellow spots, and are mostly concentrated on the sunny side of the plant.
Biological Invasion: Attack and Defense in the Microscopic World
Diseases and pests such as (T-J) disease and red spider mites cause yellow leaves with diffusive characteristics. According to statistics from the Chinese Society of Plant Pathology, 78% of pest-infested yellow leaves are accompanied by net-like leaf veins retaining green. It is recommended to use biological control methods, release natural enemies such as predatory mites, and配合 periodic prevention with Bordeaux mixture.
By improving the cultivation substrate (recommended peat: perlite = 3:1), installing a soil moisture monitor, and setting up a physical pest control net, the probability of yellow leaves can be reduced by more than 90%. Regularly observing the back of leaves and promptly treating initial lesions are the keys to maintaining the health of osmanthus.