Why Green Plant Leaves Turn Yellow and How to Fix It

Leaves are the main organs for photosynthesis in plants and also the organs for transpiration. They are generally divided into three parts: the leaf blade, the petiole and the stipules, and their color is usually green. So, what causes green plant leaves to turn yellow? How do you fix it?

1. What causes leaves to turn yellow?

Cause 1, alkaline soil: many plants are suited to growing in slightly acidic soil. If the soil is alkaline, it becomes hard in texture, caked into clods and poor at letting air and water through, and the plant shows green turning to yellow between the old leaves and the veins.

Cause 2, overwatering: for plants that do not tolerate waterlogging, if they are watered too much, the air in the soil is pushed out by the water and outside air is blocked from entering, so the soil becomes extremely short of oxygen and the roots cannot get the oxygen they need; the young leaves or leaf tips turn yellow first.

Cause 3, underwatering: for plants that like moisture, if they are watered too little, the leaves turn yellow from lack of water. This is yellowing from water shortage: the old leaves turn yellow, then the newly grown leaves gradually turn yellow too, and the edges of many leaves go from yellow to withered.

Cause 4, temperature too low: for plants that are not cold hardy, if the temperature is too low, the plant suffers cold damage, which makes the leaves turn yellow and in severe cases can cause death.

Cause 5, lack of light: for light-loving plants, if they lack light, they cannot carry out photosynthesis, which makes the leaves turn yellow, and in severe cases the leaves drop off or the plant even dies.

Cause 6, strong sun exposure: for plants that like shade, putting them in strong sunlight makes the leaf margins and leaf tips turn yellow and dry out, and the parts directly exposed to the sun develop yellow patches.

Cause 7, too little fertilizer: some plants have a very high demand for fertilizer. If too little is applied, the plant cannot take up enough nutrients, so the old leaves turn yellow first and the new leaves turn yellow right after.

Cause 8, too much fertilizer: generally you should not apply too much fertilizer, otherwise it damages the roots and burns the seedlings, which makes the leaves turn yellow and curl at the edges, with the leaf tips gradually withering and turning yellow, and in severe cases the plant dies.

Cause 9, pests and diseases: the leaves may have caught a disease or be affected by insect pests, which harm the leaves and make them turn yellow.

2. How do you fix yellowing leaves?

1. Solution for yellowing leaves caused by alkaline soil: you can use acidic fertilizers such as aluminum sulfate, ferrous sulfate, sulfur powder, ammonium sulfate, ammonium nitrate, superphosphate, monopotassium phosphate and potassium sulfate in the soil to neutralize the alkalinity in a targeted way; you can also replace the soil with one rich in organic matter.

2. Solution for yellowing leaves caused by overwatering: put the plant somewhere ventilated and with plenty of light so the water evaporates as quickly as possible; you can also add some completely dry soil to the pot to increase water absorption; or simply change the soil, or switch to a pot with excellent drainage.

3. Solution for yellowing leaves caused by underwatering: water promptly and water thoroughly, then keep the plant in a cool place.

4. Solution for yellowing leaves caused by low temperature: raise the temperature and keep the plant in an environment at a temperature suitable for its growth.

5. Solution for yellowing leaves caused by lack of light: if it is summer, put the plant somewhere with plenty of light and let it slowly return to normal, but do not put it directly in the sun; if it is spring or winter, it can be placed directly in the sun.

6. Solution for yellowing leaves caused by strong sun exposure: cut off the badly scorched leaves and shade the plant until it recovers; or keep the plant in a cool place and the scorched spots will slowly return to normal.

7. Solution for yellowing leaves caused by too little fertilizer: apply more fertilizer, such as urea, rotted fertilizer cake water, phosphate fertilizer, plant ash and potassium chloride fertilizer; apply whichever nutrient is lacking.

8. Solution for yellowing leaves caused by too much fertilizer: rinse and dilute the fertilizer in the potting soil with clean water, then put the pot in a cool place and wait until the soil is slightly dry before returning to normal care; or wash the plant roots clean with water, replace the growing medium and repot.

9. Solution for yellowing leaves caused by pests and diseases: first pull out the diseased plant, then move it to a ventilated place and spray it with a pesticide for pest and disease control.

The causes of green plant leaves turning yellow include alkaline soil, overwatering, underwatering, temperature too low, lack of light, strong sun exposure, too little fertilizer, too much fertilizer and pests and diseases, and different causes have different solutions.