I have this plant in my garden but it only appears to flower every second year. I got it from a friend and it's lovely when it does come into flower.
We call it "The Oyster plant" This plant is called Acanthus Mollis and grows wonderfully here in Australia...( some times a weed if planted in the wrong place).I chop mine up every winter and make lots of new ones and yes poppy you do have a great range of plants in your garden..( I love your Dahalia)