arborvitae emerald green
Hello, I just planted a few dozen 4 foot emerald green arborvitae in April. I have been watering them once a week up until about a week ago. How often should I water them now that cooler weather is approaching?
Washington County Maryland
During the growing season, spring to fall, plants lose a lot of water through their leaves (or needles) from evaporation. Roots are drawing water out of the soil. Also, water evaporates directly from the soil. When temperatures get colder, evaporation slows from soil and, of course, deciduous plants lose their broad leaves. Roots are not drawing up a lot of water to support growth. So, danger of too dry soil lessens.
While we occasionally do have a drought in the fall, usually you can let up on watering in the fall. Be sure the soil is moist going into winter. You don't want the ground to freeze when it is dry. But, you probably don't need to water during the winter at all. Once the ground is frozen, water can't penetrate the soil at all.
Incidentally, when warmer weather returns, water as needed. Avoid relying on too strict a schedule. Plants like about 1" of water a week, so supplement rainfall as needed.