John wrote after
Nick Maclaren wrote:

Check over-watering, use of alkaline water and something eating the
roots. You are probably overfeeding it, too - citrus do fairly well
on benign neglect.

Once I went over to summer feed, I was getting some leaf drop,
especially on branches that bore fruit. I assume this is down to
over-watering. I didn't water until the top surface dried out, but it
looks like I will have to neglect the plant.

However, I have plenty leaf growth on newer branches.

Some brochures state that citrus should be watered every week in summer?

I usually grow Bizzy Lizzies in the citrus pots and water when they start to
wilt.
Looks pretty and does a good job as an water indicator.

--
Regards
Bob Hobden
17mls W. of London.UK