Answer: The poor color is an indication of root stress. I'd water as usual then wait 3-4 days and dig down to see how moist the soil still is. If it is moist 2-3" beneath the soil surface, you won't need to water for another 3-4 days. If it is on the dry side, go ahead and water. Most landscape trees and shrubs need at least one inch of water per week, especially during the spring and summer periods of fast growth so be sure to water deeply once a week. Aside from watering issues, your emerald arborvitaes sound as though they are acting normally. Although they are considered evergreen, the oldest foliage does eventually die. That's the foliage on the inner part of the plant. You can reduce the appearance of this dieback by lightly pruning the plants each spring which will force growth behind the pruning cuts and will also encourage new growth at the ends of the branches. Together, all this new growth will make the shrubs fuller and greener throughout. Best wishes with your landscape!
Q&A Library Searching Tips