“Changing Times” magazine wants us to get our heads screwed on straight about watering our gardens, especially since summer is coming on and it’s easy for things to dry out and for our gardens to suffer harm. First: Do you water because the plants are “thirsty” and need a drink? Do you sprinkle them lightly after a hot day to cool them off? Do you avoid mid-day watering because it sunburns leaves? Do you withhold water from seedlings so they’ll send their roots deeper and wind up stronger, more drought resistant plants? All wrong. These notions arise from thinking plants need and use water like humans. They don’t. They’re plants, after all.
What your plants need and the soil requires is to be moist. Not soaked, but moist down to a foot, where the great majority of your plant’s roots take up moisture and nutrients. In the loosest and lightest of soils, it takes at least an inch of water applied to the surface. I won’t go through all the math here, but it has to do with infiltration rates and so forth, and the bottom line is that you’d have to stand in your garden with a hose for upwards of five hours. When was the last time you did that?
And remember, we said “moist,” not “soaked.” Plants take up water through their roots, of course, but it’s not like putting a straw into a glass and drinking. Plants can only use water in its vapor form. They can’t take up liquid water. In fact, if you put a plant in a jar of water, it will soon show the same signs of drought as a plant that has no water at all: wilting, stunted growth, and such like. Plants don’t “drink.”
As to depriving young seedlings of water so they’ll grow extra-long roots: plants need water at all stages of their growth so they can grow. If deprived of water, they’ll be stunted, leaves won’t develop properly and the energy needed from them to provide for the produce will be missing. You’ll have a poor harvest.
One major take-home point: to use water correctly, you must mulch. This prevents evaporation, and keeps the soil from forming a crust that makes further waterings just run off. It doesn’t matter what you mulch with – straw, hay, black plastic, leaves, grass clippings – just mulch thoroughly and thickly, water either day or night. Plants grow at night, and make food during the day, and need water for both activities. Just be sure you give it the time needed to get the water deep into the soil, at least a foot down.
Source: “Changing Times” magazine.