If you39re new to alliums this is a fantastic collection to get you started33 these popular rhs agm varieties produce spherical architectural flower heads in may and june perched on stiffly upright stems as the flowers fade attractive seed heads remain which become straw coloured as the season progresses persisting throughout autumn dot 39allium lover39s collection39 among herbaceous perennials at the front of borders or in patio containers where they will attract bees and o