I planted an Acanthus Mollis at the back of a raised bed 3 years ago. The soil is free draining but good structure and the border gets morning and early afternoon sun. The plant seems healthy with lots of leaves, yet it has never flowered and there are no signs of emerging flower bracts this year. Last year I was told it could be slugs so I pelleted the centre of the plant this spring. I would love it to flower, please can anyone help.