TheNaturePlanet

Don't panic if your lemon tree has yellowing or falling leaves! Identify the cause and take targeted measures, and it will soon regain vitality. We've compiled super practical solutions that even beginners can follow!


### 1. Water Issues

#### Root Rot Due to Waterlogging
- **Symptoms**: Lower leaves turn yellow first and fall off easily when touched; leaf tips turn brown; potting soil is sticky and wet.
- **First Aid**: Stop watering immediately. Remove the plant from the pot and cut off rotten roots (blackish-brown, slimy roots). Repot with new soil mixed with leaf mold and perlite (3:1 ratio). Place ceramic granules at the bottom of the pot to prevent waterlogging. Avoid watering for 1 week to allow the plant to recover.


#### Leaf Drying Due to Water Shortage
- **Symptoms**: Leaves curl and become brittle; new leaves turn焦黄; potting soil is dry and cracked.
- **First Aid**: First, water a small amount along the edge of the pot, then thoroughly soak the soil after 10 minutes. Spray the leaves with water 1-2 times a day to increase humidity. In summer, water when the top 2cm of soil feels dry.


### 2. Nutrient Deficiency

#### Iron/Magnesium Deficiency
- **Iron Deficiency**: New leaves have green veins but yellow leaf flesh (resembling a yellow mesh). Spray with 0.2% ferrous sulfate solution (2g per 1 liter of water) once a week.
- **Magnesium Deficiency**: Old leaves show inverted "V"-shaped yellowing at the edges. Water with magnesium sulfate solution (3g per 1 liter of water) or bury decomposed bone meal.


#### Infrequent Repotting
- **Symptoms**: The entire plant's leaves turn yellow and lack luster; growth is stunted; potting soil is compacted.
- **Solution**: Repot every spring. Use a mixture of nutrient soil and decomposed sheep manure (5:1 ratio). Bury slow-release fertilizer at the bottom. Remove 1/3 of the old soil while retaining the root-protecting soil.


### 3. Environment and Pests/Diseases

#### Insufficient Light
- **Symptoms**: Branches and leaves grow excessively long and thin; leaves are pale yellow; few flowers bloom.
- **Solution**: Move the plant to a south-facing balcony to ensure at least 6 hours of direct sunlight daily. Provide slight shade at noon in summer.


#### Red Spiders/Scale Insects
- **Red Spiders**: Small white spots on the undersides of leaves and leaf curling. Spray with bifenazate, ensuring both sides of the leaves are covered.
- **Scale Insects**: White/brown lumps on branches. Spray with buprofezin or wipe the insects with alcohol-soaked cotton swabs. Repeat after 5 days to consolidate the effect.


### 4. Daily Care Tips
1. Fertilize with dilute potassium dihydrogen phosphate (1:1000 ratio) frequently but in small amounts. Avoid using uncomposted organic fertilizers, as they may burn the roots.
2. In northern regions, water with citric acid solution (1ml per 1 liter of water) once a month to adjust soil acidity, or bury ferrous sulfate to prevent alkalization.
3. Stop fertilizing when new leaves turn yellow. Resume fertilizing after adjusting soil acidity and controlling water to help the plant recover. For severely diseased plants, prune weak branches and replace the soil after disinfection.


In short, by following these methods, the problem of yellowing and falling leaves will be improved quickly.
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