If you want a late-season pollinator magnet with a bold, upright presence, plant Eupatorium fistulosum 'Jojo' (Hollow Joe Pye Weed 'Jojo') where it can stay evenly moist and show off its domed flower clusters.
In summer into early fall, you will get billowy, pink-to-purple blooms held above sturdy stems that bring in butterflies and many other pollinators. Leave the dried flower heads standing into winter if you like added texture, then cut stems back to the ground in late winter before new growth starts.
Give it room to mature: this selection is typically about 36-48 in. tall and can spread about 36-48 in good conditions. Full sun produces the strongest stems and best flowering but it also performs well with part shade especially where afternoons are hot.
For best results, plant in rich soil that holds moisture, and mulch to help keep the root zone cool and damp. It is a natural fit for rain gardens, low spots, pond edges, and native or pollinator plantings. Water regularly during dry stretches, particularly in the first season while roots establish.