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.

In a wide variety of habitats and forms, from familiar garden bedding annuals (L. erinus), to stately border perennials, the two native forms in the British Isles are relative oddities: one a small-flowered plant of southern damp heaths, the other an emergent aquatic from Scottish lochs. Irrespective, the flowers are always bilaterally symmetrical and insect-pollinated: the showy border perennials are a major draw for long-tongued bees and butterflies, while the leaves are eaten by larvae of a number of generalist garden moths.