Causes of yellow leaves in Milan and how to deal with them
As an aromatic ornamental plant, milan flowers often confuse conservators with yellowing leaves. This paper combines the three core dimensions of light regulation, soil improvement, and water management to systematically analyze the causes of yellow leaves and provide operable solutions. In-depth analysis of the causes of yellow leaves in Milan flowers and yellow leaves caused by light imbalance Milan is a typical strongly positive plant that requires more than 6 hours of direct light every day. Insufficient light can lead to inhibition of chlorophyll synthesis, which is manifested by yellowing of new leaves and fading of old leaves. Pay attention to special seasons: full sunshine in spring and autumn, 30% shade is required from 11 to 15 in summer, and a fill light should be used to maintain the illuminance of 2000 to 3000lux in winter. The soil pH is abnormal. Milan's most suitable growth environment with a slightly acidic pH of 5.5-6.5. The alkaline water (pH 7.5 +) in the north can easily lead to fixation of iron and chlorosis between veins. It is recommended to test the pH value of the soil every quarter. When changing soil, use the ratio of humus soil: peat soil: perlite =5:3:2, and add 1% sulfur powder to adjust the acidity. Misunderstanding of water management The principle of "seeing dry, seeing wet" needs to be flexibly applied: keep soil water content at 40-60% in spring and autumn, increase it to 60-70% during high temperature periods in summer, and control water to 30% in winter. The watering timing is judged by bamboo stick testing (the humidity is observed 2 minutes after insertion into the soil) to avoid stagnant water and rotten roots or drought stress. The systematic treatment plan is phased in light regulation and adjustment of the yellow leaves immediately at the beginning, and the south-facing balcony is the first choice. It is recommended to use a full-spectrum plant lamp for filling light, replenish it for 2-4 hours a day, and keep the lamp distance of 50cm to avoid burns. Severe yellow-leafed plants need to be sprayed with 0.1% ferrous sulfate solution on the leaves. Soil improvement technology Keep 1/3 of the protective soil when changing pots, and the new soil needs to be disinfected at high temperature. Add 5% pine needle soil to enhance acid retention, and mix bone meal to supplement calcium. Add EM inoculants when watering root-fixing water after pot change to promote root recovery. Intelligent water management recommends using a soil hygrometer and setting 40% as the watering threshold. Use the dipping basin method to replenish water more evenly, lasting for 15 minutes each time to allow the soil to fully absorb water. In the rainy season, it is necessary to erect a rainproof canopy to avoid too wet the soil.
Through a three-pronged approach of light regulation, soil improvement, and precise watering, combined with monthly application of alum fertilizer water (ferrous sulfate: cake fertilizer: clear water =1:3:100), the green color of the leaves can be restored in 2-3 months. Only by regularly observing the status of new leaves and establishing a maintenance log to record environmental parameters can the sustainable and healthy growth of Milano flowers be achieved.