Pentas are among the best annual summer color plants we can grow in Mississippi gardens and landscapes. Besides providing great color for us to enjoy, pentas are magnets for butterflies and hummingbirds because they are rich sources of nectar.
These plants also have great tolerance of the heat and humidity of Mississippi summers, something I wish I had more of.
One of my favorite pentas is the Butterfly series that was named a Mississippi Medallion winner in 2001. These plants add an almost tropical feel to the porch or patio, especially when mass planted in large containers.
There are many colors available, all starting with Butterfly: deep rose, white, blush, deep pink, light lavender, lavender and red. With a little TLC, they will produce flowers all summer long. Blooms are produced in clusters of five-petal flowers from spring until frost in the fall. It's common for each penta to have up to 20 clusters of flowers at any given time. Wow!
Butterfly pentas grow up to 24 inches tall and about 18 inches wide. The name "penta" comes from the Latin and means five, since each small flower has five petals. These plants are also commonly known as Egyptian starflowers.
As I mentioned earlier, pentas require a little TLC for them to bloom all summer. After bringing your plants home from the garden center, be sure to plant them in a location, whether a landscape bed or container, that gets full sun for at least six hours each day.
Good drainage is important, so if you will be planting in a landscape bed, go ahead and work several inches of good composted organic matter into the soil. On a side note, this is good advice for anything you plan to plant in the ground.
Pentas perform best with a neutral soil pH (about 7.0). Your pentas will greatly appreciate you adding a little dolomitic limestone to the soil. A word of advice: I suggest you have a soil test done at least every two to three years in your landscape beds, primarily to learn the soil pH recommendations.
While pentas make great companion plants for many garden staples, planting with azaleas and camellias may seem out of the question because of these shrubs' preference of a more acidic pH. To make it work, simply add some dolomite along with a couple of tablespoons of slow-release fertilizer to the pentas' planting holes and not to the entire landscape bed.
One final tip: Be sure to deadhead the spent flower clusters, as this promotes more flowering later in the summer. But I wouldn't wait to deadhead these plants. Penta flower clusters make great additions to any summer fresh arrangement to enjoy in the house.
Gary Bachman is a professor of horticulture at the Coastal Research and Extension Center in Biloxi.