Posted: 27/06/2015 at 19:35
Difficult position forget me not.
When he starts spraying could you ask him what he is using? Also to say what happened to your plants and your suspicions. Get it over and done with. To simply resort to spraying everything is plain daft too. The natural world is not that clinical.
You cant approach him by saying what you,think you overheard, can you?
Its about being tactful...fancy me saying that! ......
At least your neighbour will be more aware in the future.