We planted a new row of cypress trees, approx a month ago. They are about 1.5 m tall and stand in direct sunlight for most of the day. We water them regularly with DIY. At first they were doing well, but then yellow spots appeared which quickly turned brown. As of now, many of them now look completely yellow-brown and even those which remained green have yellow spots inside.
I don't see any sign of canker, the bark seems completely healthy.
What should i do to save the remaining green cyprus trees? Is there anything to do for the yellow ones?
climate: mediterraenan (tel aviv)