Mystery of the Lavender Leaf Loss

Its been raining here for days.  Well, not all day everyday - A deluge every day or every second day, but enough that the soil is constantly wet - that is a lot for Sydney and is quite unusual for us at this time of year.  All my preparations for a hot dry period have been unnecessary and instead I have been worrying more about plants in pots becoming waterlogged, or transplants not developing the roots they will need once the weather does become hot and dry.  Combined with the heat, the rain makes it very humid, and I have been concerned for the survival of plants like lavender and rosemary that need good drainage, to dry out between waterings, and good air flow.

But that is not the problem with a lavender plant that I discovered this morning......