When you want to grow something for pollinators that not only looks great, but is rich in nectar think about the globe thistles (Echinops ritro).
They flower in mid to late summer when many of our garden pollinators are on the wing, but especially timed for our new queen bees that hatch out in mid summer.
Research from the University of Bristol shows that Globe thistles (Echinops) provide a crazy amount of nectar (especially for honeybees and bumblebees). For example, a single globe thistle head gives as much nectar as 32 Cosmos flower heads, 108 rosemary flowers or 349 lawn daisy heads. Echinops arewithin the thistle subfamily within the daisy family.
The plants are perennial so once established they will persist and spread in your garden borders. They are tall and large and better suited to the back of a herbaceous border. The plants will die back for the winter and burst into growth again in spring. Easy to grow and great plants for pollinators.