Posted: 18/02/2014 at 11:39
It's quicker! Also perennials are harder to get going from seeds. But I'm not an expert at growing hardy perennials from seed. I usually buy them, divide them or take cuttings. I grow a lot of annuals from seed and veg.
I mentioned sunflowers because you did, but I've looked up the Maximilian sunflower and it's a bit different, it's a perennial that you can grow from seed for the back of the border.