Solution: Lemon trees are suitable for living in the environment of 10- 15℃. Because it needs some light, it can't be kept in the shade for a long time. You can spray water on the leaves to cool down by evaporation.
Second, the reason for watering in time: lemons can't grow without enough water, and lack of water can easily lead to yellowing of leaves.
Solution: Replenish the lemon in time. Once every 2-3 days, usually in the early morning, which is more conducive to absorption. Don't use too much water to avoid the formation of stagnant water, as long as the basin soil is wet.
Third, the reason for fertilization: lack of many nutrients will lead to yellowing of lemon leaves, such as iron deficiency and nitrogen deficiency.
Solution: Iron deficiency often leads to the yellowing of lemon mesophyll, and a certain amount of ferrous sulfate needs to be added when watering. In addition to iron supplementation, it can also increase soil acidity and is more conducive to growth. Lack of nitrogen will make its veins yellow, so compound fertilizer with balanced nitrogen, phosphorus and potassium should be used when fertilizing, and nitrogen fertilizer should not be applied in a partial way to avoid its vain growth.
Fourth, proper shading reasons: the growth of lemon trees needs light, but direct light will also be unfavorable to them, leading to yellowing of leaves.
Solution: At noon in summer, you need to shade the lemon tree. If it is a potted plant, it can also be placed in a semi-shade to receive some scattered light. Shading time should not be too long, otherwise it will affect its flowering and fruiting.