Hi. I have a compact Hinoki cypress (Chamaecyparis obtusa ‘Chabo-hiba’), that was gifted to me from the Arnold Arboretum collection last November. I recently repotted it and it was doing well, very green and perky. I have it outside, but we had a sudden heat wave in the Pacific Northwest and all of a sudden the leaves started browning and drying out. I’m not sure if this was stress on the tree from the extreme temperature change and sun light, or something else? It seems to be getting worse over the last few days. What is causing this? And what should I do?

When you get a heat wave. Water more frequent.

Heat.
Hinoki likes it wet.