Why can't you water the flowers with cold water in summer?

At noon in hot summer, the temperature is very high, and the leaf temperature of flowers can be as high as 40 degrees Celsius, with strong transpiration and rapid evaporation of water. Roots need to constantly absorb water to supplement the loss of transpiration on leaves. If cold water is poured at this time, although the water in the basin soil is increased, the root hairs are stimulated by low temperature due to the sudden drop of soil temperature, which will immediately hinder the normal absorption of water.

At this time, because there is no preparation in the flower, the stomata on the leaf surface are not closed, and the balance between supply and demand of water is lost, which leads to the change of leaf cells from nervous state to wilting state, which makes the plant appear "physiological drought" and the leaves are burnt, which will cause the whole plant to die in severe cases. This phenomenon is particularly obvious in herbaceous flowers, such as geranium, dill and aster. What are the most taboo to splash cold water at noon on a hot day? So it is advisable to water the flowers in the morning and evening in summer.