Mary Fisher wrote:
Pests were my first thought because the browning is irregular but I looked
very carefully and found nothing. And it's not cat spray :-)

How truly bizarre. My neighbour has lost her enormous one, in a pot for
years and her neighbour too ... They both asked me why mine is still
going. I had absolutely no idea because I have one in the ground and
one potted. The potted one never looked really healthy, but I'm used to
it on the outside of my kitchen window and it's under the gutter so it
receives lots of water. It's pot is home to several kind of mosses -
pretty. I eat the leaves of the one in the ground - it's been there
perhaps 8 years. Never pruned it as I harvest young and old leaves
twice a year.

Now, did the bay problems started in the spring or summer?! Both my
neighbours's bays saw signs of distress around May. Something came to
mind too, is it perhaps because it is not harvested sufficiently? I
know that my neighbour didn't pick leaves from it. She just likes the
tree...