On 09/04/2012 17:20, Hedgecop wrote:
Hi All,

I have a Bay Tree on which the leaves are turning brown and falling off.
The tree has been very healthy for the last 5 years and this has only
started happening over the last 4 months. I have tried regularly
spraying it with various bug killers but with little or no success. I
have attached some photos and would really appreciate if anyone has any
ideas as to what the problem may be and how to solve it.

I would be inclined to suggest that the damage to the tree is mostly due
to the wetting agents in the various bug killers damaging the waxy
coating of the leaves. Your best bet is probably to leave well alone for
now unless you can actually identify the pest with an eyeglass.

Examine the leaf stems for scale insect and if appropriate apply a
systemic insecticide but don't consume the leaves for ages afterwards.
The tree looks too big to go over with a stuff brush dipped in meths.

If all else fails and you manage to kill all the top growth by use of a
wetting agent (in my case diluted washing-up liquid) since I wanted the
plant for culinary use a decent sized plant will usually come back from
the roots even after all the upper parts are stone dead.

Hope this helps.

--
Regards,
Martin Brown