Help – Mexican Orange blossom dying plant by plantStarting with one plant and spreading along

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There hasn't been any toadstools at the base in the autumn? This death is typical of honey fungus but you usually have toadstools in august-October.
See what others on the site suggest.

Thank you very much for the reply - There has been no fungus I have seen I'm afraid

The blackening of the leaves and their stems reminds me of phytophthora. This is another form of potato blight. Look it up by all means but I don't think there isn't any remedy for this disease. Perhaps cut out any affected parts and give it a good feed and see what happens. Aucuba is another shrub which can suffer from this problem.

Thank you Jimmy - I will do some research. What surprises me is that ours is the only one in the neighbourhood affected. I also note that the immediate neighbour has a row of hydrangas and the one adjacent to the 'dead' end of our choisya died. I need to ask him more. Soil issue? Contamination? So sad - grew them from wee little things.

Yes jimmy may be right, to be honest I have never known Choysia be affected by anything, all the gardens I look after , have Choysia and all seem in good health, there seem to be so many shrubs these days that are getting viruses etc, and some plants like laurel, holly even ivy which are so tough are being threatened, I noted last week a lovely holly tree with its leaves riddled with what looks like a type of leaf miner, I planted a new Choysia sundance for a client in early March, it’s doing well but last week I noted it had thousands of very small knat like flys flying all round it, never seen this before, so as a precaution I have sprayed the shrub with bugclear, other shrubs that I note are more affected these days are sambucus black lace and physocarpus with types of black fly.

Thank you Julien (and Jimmy) - RHS site describes the symptoms as very similar.

My neighbours say fuchsia's have a recent enemy spoiling them at the moment in their front borders :(

If al the dying plants are in a more or less straight line I'm wondering if there could possibly be something underground that's been leaking something poisonous to them. A very long shot and perhaps a silly suggestion but who knows...

Thx Steragram. Apparently the neighbours Hydrangea was unconnected - he moved the end one twice, it died back but is starting to recover - I'm going to look at the roots of the latest dying one. I found a picture of what phytophthora can look like just below the surface