I have just come inside after having to replant a once beautiful coleus which had been massacred overnight just like the OP's photo, only mine was a smaller plant, newly bought but plenty of leaves and healthy.
I've put it into the pot it was bought in for now, with fresh compost and put the pot elsewhere in the courtyard. It was sited next to a blooming RUDBECKIA, the one with yellow petals and dark red throat. It also was damaged with the petals of two flowers eaten away.
What can I do to stop a repeat?
I had to remove all clumps of yellow primroses earlier this year due to leaves and petals being eaten. No slugs seen in daylight nor slimy trails.
I am in South Surrey UK
Advice appreciated.
