Arborvitae and hinoki false cypress dying
Hello - We planted a hinoki false cypress this spring and it suddenly turned brown and died about two weeks ago. Over the past week, we've noticed that the arborvitae next to it is turning brown and appears to be dying. The three attached photos are the hinoki cypress, the arborvitae, and a close up of the needles turning brown. Any suggestions would be appreciated. We love the arborvitae and it is adjacent to some beautiful junipers that we don't want to lose!
Hinkoki cypress grows best in full sun in a well drained soil.Some reasons for decline include poor planting techniques, poor drainage, excessive mulch, etc. See the planting process on our website https://extension.umd.edu/hgic/topics/planting-process
Arborvitae - this looks like normal needle drop and fall color. No control is necessary. Simply monitor the growth of the plant. Keep watered during dry periods and make sure mulch is no thicker than several inches.
We thought that we may have planted our hinoki in a bad place, and you just confirmed it. We'll keep an eye on the arborvitae and make sure we keep it watered.