Pentas are semi-tropical shrubs grown as annuals and are one of the best flowering plant/shrubs for butterfly-attracting. They bloom 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 nectar-rich flowers grow in clusters over a long blooming season in the vibrant red, pink, and purple shades that act as a butterfly beacon. Bees like them too, so consider adding this plant to a landscape space you want buzzing with activity. 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. Pentas flowers can be used as annuals during summer in climates colder than United states Department of Agriculture zone 10. They will simply die back when the cold weather arrives, or you can try to growing Penta plants indoors.