buying perennials when sowing from seed is difficult

These veronicas are one of those perennials very difficult to sow from seed. I bought the Royal Candles variety a few years ago but they didn't come up this year and I do love them so decided to invest in a couple more plants. The garden centre also had Ulster Blue Dwarf which looked very attractive so I bought one of each.

Veronica Ulster Blue Dwarf

Veronica Royal Candles

This was in my Weed Guide under mystery plants but now that buds are appearing I think I had a few flowers on this last year and it's either greater or lesser knapweed which I had forgotten. I don't seem to have any pics of it from last year - very remiss of me especially if I'm not taking better notes.

This suddenly appeared in the garden next door. It looked a lot like a foxglove before the flowers opened this morning. Now I can see it looks like a verbascum which I don't see anywhere around here so I have no idea where it came from. I don't know much about them so don't know if they are a known self-seeder.