|Why are my trees turning brown. Why are my trees turning brown? they are small trees and I've had them a year, so they are established. They will grow to 12-15ft. They were growing well, until about two weeks ago.I water them once a day unless the temperature reaches the high 80's or 90. I water twice on those days.|
|Most landscape trees and shrubs need only about an inch of water per week, even during the hottest months of the year. It is generally recommended that you water deeply once each week; twice each week if weather is extremely hot. Daily watering is excessive and overly moist soils can be depleted of oxygen, something the roots need. Without adequate oxygen, the roots will suffocate. Your arborvitaes sound as though they are suffocating from the excessive applications of water. I'm not sure they can recover, but you can try to help them by immediately stopping your daily watering routine. Wait 3-4 days and dig down into the soil. If it is still moist 2" below the surface, you won't need to water for another 3-4 days; if it is dry, it's time to water.
I hope your shrubs recover!