John wrote
Ragnar wrote
Another possibility is Phytophthora, a sort of fungus-like organism that
causes foliage to turn brown, often down one side of the plant at first,
before the tree eventually dies. It killed a whole cypress hedge of mine
last year and affects conifers and fruit trees. There is no cure.
Similar symptoms are caused by Honey Fungus.


My apple tree was suffering from candyfloss like stuff, but this year it
seems quite healthy.
My almond tree took several years to die.

If there is no cure is there anything suitable to replace them as a
screen?


Candyfloss stuff on your aplple tree is Woolly Aphid, spray in early spring.

As it's your Leylandii, Privet and Almond that have died I would suggest it
is probably Honey Fungus, little else would kill all those other than a
neighbour with a bottle of poison.

--
Regards
Bob Hobden
just W. of London