Pentas is one of the best butterfly-attracting plants around. It blooms all summer long, even during the hottest weather, with large clusters of starry blooms that attract butterflies by the dozens as well as hummingbirds. The plant grows well in containers and in the ground — and it can even make a good houseplant if you have enough light. It does best in full sun and moist, well-drained soil. Pentas is grown as an annual in most parts of the country.