What to Do When Geranium Leaves Turn Yellow
As a widely popular ornamental flower, the yellowing of geranium leaves has troubled many gardening enthusiasts. This article systematically sorts out 5 common causes and corresponding solutions, using scientific care to bring vitality back to your plants.
Physiological Yellowing Phenomenon in Plants
Metabolism of New Leaves
New buds often show a light yellow color at the beginning, which is a normal phenomenon during the chlorophyll synthesis process. The leaves will gradually turn green as they mature. Maintain the current care conditions and avoid frequently moving the pot.
Replacement of Bottom Old Leaves
The natural yellowing of the first 2-3 leaves at the base of the plant is part of metabolism. Cleaning 1-2 old leaves per month can promote the growth of new branches. It is recommended to use a sterilized pair of scissors to cut diagonally at the base of the leaf stalk and apply wood ash to the cut to prevent infection.
Environmental Adaptation Issues
Severe Temperature and Humidity Fluctuations
When the day-night temperature difference exceeds 10°C or the humidity changes by more than 30%, the plant will produce stress-induced yellow leaves. When repotting, follow the progressive principle: place the pot in the target environment for 2 hours/day, completing the transition in 5-7 days.
Sudden Change in Light Intensity
When suddenly transitioning from full sunlight to indoor scattered light, it is recommended to use a shading net as a transition: first cover with double-layer shading net (70% light blocking) for 2 weeks, then switch to a single-layer net (50% light blocking) for 1 week.
Solutions for High-Temperature Stress
When the temperature is persistently >32°C, the root absorption efficiency decreases by 60%-80%. Suggestions: 1. Raise the pot base by 3 cm to enhance ventilation. 2. Spray chelated iron fertilizer (diluted 1500 times) on the leaf surface. 3. Provide shading at noon and sprinkle water on the ground to cool down. 4. Switch to a breathable container like a ceramic pot.
Essentials of Scientific Water Management
Recognition of Drought Symptoms
When the soil moisture content is <30%, the leaves turn yellow from the bottom up, and the leaf stalk droop angle is >45°. Emergency solution: Use the immersion pot method to add water, with the water level not exceeding 2/3 of the pot height, soak for 15 minutes, then drain.
Accumulated Water Treatment Specifications
When signs of root rot appear, immediately remove the pot and trim the blackened roots, soak in a 1000-fold potassium permanganate solution for 30 minutes, and repot using a new matrix of perlite:vermiculite (3:1).
Comprehensive Pest and Disease Control
In the early stage of leaf spot disease, spray with mancozeb 800-fold solution once every 7 days for 3 times; during the outbreak of aphids, alternate the use of imidacloprid and matrine; regularly spray with Trichoderma harzianum to prevent root rot.
By systematically diagnosing the causes of yellow leaves and combining precise care measures, more than 90% of yellowing issues can be improved within 2-3 weeks. It is recommended to establish a care log, recording key data such as temperature, humidity, and fertilization frequency, to achieve scientific management.