Lobelia
One of the more commonly grown lobelias, the cardinal flower, from North America is amongst the most elegant for late summer, taking over from the candelabra primulas and needing the same deep, rich, moist soil. They are not averse to sunlight, but will flower in part shade. The individual flowers can be very extravagant, with two upper and three lower petals, reminiscent of an elegant, flowing ballgown. With other flowers, the petals are fused together, leaving the fertile stamens free to dab their pollen o the next amenable pollinators. Either way lobelias can add a touch of the exotic and vibrant colour to a late border. Similar to hosta, watch for slugs and snails when the foliage first emerges.