About a year ago we planted six Taxus baccata 'Stricta'. Five of them are doing great, have deep green color, grew about a feet. One (in the middle of the row) was doing great as well until about 2 month ago. In the last two month it become as deep green and it is becoming yellow (see photo).

Currently they are about 7' tall, planted on the north side of the fence. They still get direct sunlight and a lot of indirect. They all have individual bubbler which is on for about 5 min every 3 days.

Any recommendations?

Thanks,

Vadim