The pentas lanceolata is a type of flowering plant that is a member of the Rubiaceae or madder family. Pentas are sometimes called butterfly pentas, Egyptian starcluster, or star flower. Their bright and colorful flowers make them a popular flower for containers on patios and backyard decks, but they can also make an attractive showing as a garden border.
Pentas typically grow from 24 to 36 inches (60-90 cm) in height and have dark green, lance-shaped leaves that are considered somewhat velvety or furry. They produce small, five-petal, star-shaped flowers that grow in clusters. Blooms may be seen in shades of red, purple, pink, white, or lilac. Some plants may even produce flowers that are two-toned.
Although pentas are considered annuals, they often grow as perennials in areas where the winter is typically mild. The blooming time is usually from spring to autumn, but when grown in green houses, plants may bloom all through the year. They are recommended for growing in US Department of Agriculture hardiness zones 8 through 11.
While pentas are considered to have a moderate to high level of drought tolerance, they actually prefer a slightly acidic soil that is well-drained and somewhat moist. A 2- to 4-inch (5.1-10.2 cm) layer of mulch applied around the base of the plants can help the soil to retain moisture during the hotter days of summer. When used in a garden space, plants should be 24 to 36 inches (60 to 90 cm) apart to allow for spreading. They grow best in full sun to part sun, but will still bloom in partial shade. If fertilizing is desired, an all-purpose fertilizer with a 6-2-4 or 4-2-3 analysis is best.
A favorite treat for butterflies, bees and hummingbirds, pentas are ideal plants for butterfly gardens. When planted in a garden, the pruning or pinching back of the branches during the early spring will help to encourage new growth and produce stronger flower stems in the summer. As the blooms fade, the removal of flower heads will also help to promote the growth of more blooms.
There are two methods of propagation for pentas: using softwood cuttings or growing the plants from seed. When growing from seeds, the seed heads remain on the plant and are allowed to dry. Once the seed heads are dry, they are removed and the seeds are collected. Since the seeds do not store well, they are sown as soon as possible.