Page 16 - December 2023 Gears and Ears

Inside the Garden

By Karen Ehrlich

December 2023
Inside The Garden: Spotlight On Annual Vinca

By Karen Ehrlich

Annual Vinca, also known by its scien3fic name
Catharanthus roseus, or Madagascar Periwinkle
is typically an annual but is grown here in Florida
as a perennial. It has flowers and foliage that
resemble impatiens, but rather than being a shade
lover, annual vinca is a perfect choice for sunny
locations. Rated for USDA Plant Hardiness Zones
9a through 11 makes it an excellent choice for
Central Florida gardens. However, annual vinca is
not cold-hardy and prolong cold temperatures
will cause plants to die off.

The foliage is dark green and leathery. Depending
on the variety, fast-growing vinca is 6 to 18
inches tall with a similar spread. Annual vinca
plants bear single blooms with five petals that
frequently touch each other. Many varieties
feature a contrasting eye and flower colors range from white with a yellow or red center to dark pink with a darker red
center. It thrives in sandy well drained soil that is common in most Central Florida gardens. It grows in full sun to partial
shade and is relatively drought-tolerant once established. Take advantage of the fast growth habit of vincas. Buy a six-
pack of vinca plants as a filler for any blank sunny spot in the garden border where your perennials haven’t matured yet.
But be aware that all parts of catharanthus roseus are toxic if consumed by humans or animals. However, some alkaloids
produced by the plant have amazing medicinal properties. In the 1950s, scientists discovered that two of them,
vinblastine and vincristine, could treat various types of cancers.

Types of Annual Vinca
Top varieties of annual vinca include:
• Cooler series: A good choice for gardeners with cool summers.
• Heatwave series: Plants have a very compact growth habit.
• Mediterranean series: Plants trail to 2 feet; use in containers and hanging baskets.
• Pacifica series: An early bloomer.
• Soiree Double White: A novelty in the vinca world, this variety produces double flowers for a full, lush look.
• Stardust series: Flowers feature a white starburst in the center. Look for the All-America Selec3ons' award-
winning "Stardust Orchid."
Common Problems with Annual Vinca
Brown Spot on Leaves: Annual, vinca can succumb to numerous fungal diseases, like leaf spot, botrytis blight, even root
rot. These kinds of problems happen because of dampness, and lack of airflow. This problem is easily fixed by thinning
out the plants — trim away all affected leaves with a clean, sharp garden shear—and applying a fungicide.

Yellow, Wilted Leaves: If your annual vinca’s leaves are yellowing and wilted, it’s likely your plant is getting
too much water. Stick your finger into the soil: Is it soaked? Yellowing, wilted leaves are a sign of too much
moisture, which is easy to remedy.

16