[adri]

I appear to have botrytis on a number of lavender cuttings I have in the polytunnel.  Out of 100 cuttings it seems to be on around 15 so I'm worrying that it's going to get to the lot.

Any suggestions as to fungicide/treatment?

Thanks in advance

Adri

[mumofstig]

Medwyn uses lemon juice on tomatoes..

to spray the affected area with acid and that is best done with PLJ, pure lemon juice. Another type of acid that will do the trick is vinegar, both of these are to be used neat but not to spray the whole plant.
If it's only in the leaf then cut it out and spray only the stalk or main stem area where the disease is noticeable. This is actually what they do on a commercial scale by applying the juice or vinegar directly onto the affected part and the plant monitored from that point on. There is no need to powder or spray the cut end of a stalk or leaf as it should heal naturally.

I don't know if it would work on Lavender perhaps try cleaning off the damaged leaves and usinf the lemon on 1 or 2  as a trial? RHS says there are no chemical treatments for it now.

I'd also move the mouldy ones outside to avoid infecting the others.