Don’t Grab the Hose Yet: What Wilting Plants Are Really Telling You
Do you ever get up and enjoy a cup of coffee in your garden in the morning, noticing how beautiful and vibrant your plants look, only to come back outside at lunch with them looking as wilted as you feel prepping for your afternoon meeting. Your first thought may be to get the hose and give them more water! One of you should be perky and that afternoon coffee isn’t helping. But stop! Before you give them more water, check on those plants later as the evening temperatures have dropped again. There is a good chance the plants will be looking less tired and may have perked back up on their own. If so, you have just witnessed evapotranspiration.
Way back in elementary school we learned about the water cycle and how it delivers rain to our houses and yards. What you may or may not remember is evapotranspiration. This is when water vapor is released from the plant back into the atmosphere, allowing the evaporation of water from soil. It is a critical part of the water cycle and one that is not easily seen.
When the plant’s leaves become wilted that indicates that evapotranspiration is happening and the water on the leaf’s surface is evaporating leaving behind the sad looking leaf. This is more obvious in our hot summers than any other time of the year. When the sun is not as high in the sky (at night), the amount of evaporation lessens, so the roots are able to move enough water through the plant, to make it look less wilted.
This is why it is a great test if you are giving your plants enough water or not. If you notice the plant is not wilted at night or in the morning, then the heat of the day is getting to it, but it is fine and does not need any additional water. However, if the plant is still drooping at night and in the morning it needs more water. Depending on how long this has been happening, you may have reached the plant’s permanent wilting point and there is no return. The plant will die. Or if you catch it quickly, there is still a chance of saving the plant by increasing the amount of water you give it or the frequency, depending on your garden.
