Botanical Name: Catharanthus roseus
Plenty of sunshine will make periwinkle flower from summer through fall.
This Madagascar native is related to the Vinca species, known for its true-blue flowers. There is a resemblance, but this tropical relative has a beauty all its own. This shrubby plant has upright stems densely covered with shiny, dark-green oval leaves. The leaves feature prominent light-green midribs.
Star-shaped periwinkle flowers are small -- only 1 in (2.5 cm) across -- but they cover the plant in abundance if given enough light. Flowers are typically pink with a deep-pink throat. You may also find them in white or pale lavender.
You can buy periwinkle from a nursery or garden center in the spring and summer. Choose a periwinkle plant with plenty of flower buds -- a sure sign of a healthy flowering plant.
Let the sun shine in. Flowering plants need plenty of light to bloom. To help your periwinkle bloom, keep your plant where it'll get a few hours of sunlight every day.
Or move it outside. Growing periwinkle plant in a sunny spot outdoors for the summer will give it more blooming power. Just be sure to bring it back inside before the temperature drops to 60°F/16°C at night. It doesn't like the cold at all.
Repot in spring. Madagascar periwinkle is a vigorous grower, quickly filling a small pot in a short time. Repot when your periwinkle plant outgrows its pot, moving it up to a pot 1 size larger.
Height: 10 in (25 cm)
Light: Bright light with some direct sunlight. Plants that don't get enough light will grow tall and leggy, with few blooms. Moving it outdoors for the summer may be just the solution.
Water: Keep soil evenly moist. Plant it in a pot with drainage holes to prevent soggy soil.
Humidity: Moderate. If relative humidity falls below 50%, mist the foliage and place the pot on a tray of wet pebbles.
Temperature: Average to warm 65-85°F/18-29°C
Soil: Use a fast-draining potting mix. You can use an all-purpose mix and add a little perlite.
Fertilizer: Feed every 2 weeks with a balanced liquid fertilizer diluted by half while periwinkle plant is growing and flowering.
Propagation: Sow seed indoors in late winter or early spring. New 3 in (8 cm) stem tip cuttings can be taken in spring or early summer and planted in moist potting mix.