Gardeners admire pentas plants (Pentas lanceolata) for their bright, generous clusters of star-shaped flowers. They also appreciate the butterflies and hummingbirds that pentas attract to the garden. Do you need to worry about pruning pentas plants? Pentas in frost-free regions are perennials and can grow leggy if left untrimmed. For information about pentas plant pruning, including tips on when to cut back a pentas plant, read on.
About Trimming Pentas Plants
If you live in USDA plant hardiness zones 10 or 11, you can grow pentas as evergreen perennials. In cooler zones across the country, these shrubs, also called Egyptian star flowers, are grown as annuals.
Pruning pentas plants grown as annuals is not necessary to create a strong branch structure. However, it may help keep the shrub looking its best. One way to accomplish this is to regularly remove some of the blossoms to display indoors in cut flower arrangements. You can cut back two-thirds of the flower stalk when you start trimming pentas for cut flowers.
Deadheading pentas is another way to do pentas plant pruning. Pruning pentas plants by removing the dead flower clusters also encourages new flowers to grow.
How to Prune Pentas Perennials
If pentas are perennials in your region, they can grow taller than you are over time. Perennial pentas plant pruning may be necessary if the shrubs are looking leggy or scraggly. You’ll want to start pruning the plants when a few of the branches are noticeably taller than the rest of the plant, giving the pentas a disheveled look.
Cut the tall stems back at a bud a few inches (8 cm.) below the tips of the other branches. No need to waste the cuttings. You can root them and use them as new shrubs.
When to Cut Back a Pentas Plant
If you are wondering when to cut back a pentas plant, it depends on whether you are growing it as an annual or a perennial. Annuals only live for one growing season, so you can trim or shape them whenever you feel it is necessary.
Trimming perennial shrubs to shape can be done at any time. If you want to renew your pentas plants by doing major pruning or trimming them to a few inches (8 cm.) above the soil to rejuvenate them, wait until after the flowers fade in autumn.