Vinca, also known as Madagascar periwinkle, is a star-performing annual usually grown in containers. It’s widely considered the #1 heat-loving flower for summer color. Here’s how to grow it in the desert Southwest.
If you love flowers, but find that many annuals fade or are fussy during the heat of the summer, look no further than vinca, also known as Madagascar periwinkle (Catharanthus roseus).
These flowers are ubiquitous in containers in the desert Southwest… with good reason. These are the “energizer bunnies” of desert potted plants — they keep on going even during the worst heat waves.
Harlow Gardens, Tucson’s oldest family-run nursery, reports that vinca is consistently their top selling summer annual. Their customers love it because it flowers profusely all summer, has attractive green leaves, and can take the heat. They come in a wide range of colors from deep red to white, but are usually some shade of pink.
They are usually grown in containers but can also be planted in the ground as a bedding plant. It’s not unusual for seeds to escape their pots and reseed in the landscape.
Why I Like This Plant
- Non-stop flowers spring through fall
- Glossy, true-green leaves
- Thrives in summer heat
- Low maintenance, low-litter
- Annual that often acts like a perennial
- Attracts bees and butterflies
Things to Watch Out For
Vinca is not a low water use plant and needs frequent watering during the summer to look its best.
It’s toxic to humans, dogs, cats, and horses.
It’s a good practice to change out the soil every few years when growing it in pots. Continually planting vinca in the same pot with the same soil can ultimately lead to a disease known as vinca wilt.
Optimal Growing Conditions
If you’re thinking of growing vinca, here are the key factors to keep in mind.
Temperature
Vinca is extremely heat tolerant and can handle the heat of Phoenix. It can be grown anywhere as a summer annual, but if you hope to overwinter it, it should be grown in USDA Hardiness Zones 9 to 11.
It is not cold-hardy and dies back with the first frost. However, in climates with mild winters and occasional freezes, plants can survive and rebound in the spring, especially when protected during cold snaps.
Is vinca an annual or a perennial?
It depends.
It’s considered a perennial in zones 10 & 11.
It’s considered an annual in zone 9,
but it can come back in the spring.
Sun Exposure
Vinca performs best in full sun or part shade. Avoid exposing it to reflected heat. It appreciates a little relief from afternoon sun in the summer.
Size and Growth Rate
Vinca is a fast grower. When started from seeds, new plants start flowering within 6 to 8 weeks. Each plant reaches a size of 1 foot tall by 1½ feet wide, but it’s usually planted in groups that form mounds of color.
Soil
Whether planted in a container or in the ground, vinca needs well-draining soil to avoid root rot. It’s prone to iron chlorosis in sandy soils.
Vinca:
The Essentials
| Common Names | Vinca, Madagascar periwinkle |
| Scientific Name | Catharanthus roseus |
| Origin | Madagascar |
| Plant Type | Annual/perennial |
| USDA Zones | Zones 9 – 11 |
| Cold Hardiness | To 30℉ |
| Flower Colors | Usually shades of pink |
| Flower Season | Spring, summer, fall |
| Mature Size | 1′ high x 1½’ wide |
| Growth Rate | Moderate to fast |
| Sun Tolerance | Full, part sun |
| Water Needs | Low to moderate |
| Pests & Diseases | Vinca wilt, root rot, insects |
| Toxicity | Toxic to humans, dogs, cats, horses |
| Wildlife | Attracts butterflies, bees Deer, rabbit resistant |
How to Care for Vinca
Whether you’ve recently planted vinca or have existing plants in your yard, here’s how to take care of them to keep them healthy and looking their best
When to Plant
While nurseries are well-stocked with vinca and other summer annuals early in spring, resist the urge to plant them until your nighttime temperatures stay above 55°F.
While you may see plants for sale in the fall, you can give them a try, but they won’t have much time to get established and might not make it through the winter.
How to Water
While somewhat drought tolerant, these plants are happiest when watered frequently. But don’t let them stay continually wet. To avoid root rot, let the soil dry out between waterings.
Should You Fertilize?
To keep vinca flowering profusely, lightly fertilize once a month between spring and fall. This is especially important for those grown in pots.
How to Trim
These plants don’t need pruning or deadheading, but you can occasionally pinch them back if they get leggy or if you want to encourage bushiness and more flowers.
Pests & Diseases
Vinca can get aphids, spider mites, or whiteflies. If you see these on your plants, spray them away with your hose. If that doesn’t work, use insecticidal soap.
Vinca Wilt: Causes & Prevention
Vinca wilts when thirsty, then usually perks right up with water. But if you find that your plants don’t recover with water, they might have vinca wilt, a fatal infection that prevents plants from taking up water.
It seems there is more than one organism causing wilt symptoms including Fusarium (fungus), Phytophthora (fungus), Rhizoctonia (fungus), and Spiroplasma (bacteria).
But all you need to know is that if your plants are wilted, and don’t rebound when watered, you should assume they have vinca wilt.
There’s no effective cure, so you should remove and dispose of affected plants. Don’t plant new plants in the same soil, since the spores can live in soil for years.
You can reuse your container, but scrub it with hot, soapy water and let it dry in full sun first. Some sources recommend using a dilute solution of bleach as a disinfectant.
One preventative measure you can take is to rotate your plants to avoid planting vinca in the same soil every year.
Is Vinca Invasive?
Vinca often reseeds in desert gardens. They are usually welcome volunteers and rarely reseed to the point of being a nuisance.
However, vinca has widely naturalized around the world, including parts of the US — Florida, Alabama, and California. And in some pockets in the US, it has become invasive.
So far, it has not escaped cultivation in the desert Southwest. It’s believed its range here is limited by lack of water and winter freezes.
Vinca Cultivars
Vinca has dozens of cultivars, and new ones are introduced every year. The main difference between most of them is flower color. They come in a rainbow of colors — white, dark red, lavender, peach, and every imaginable shade of pink.
Most vinca are upright, but there are now trailing varieties that cascade when grown in pots and form a ground cover when planted in the ground. They grow half a foot tall and 2 feet wide.
Don’t Confuse Vinca With…
Vinca has many (too many!) alternative common names including:
- periwinkle
- Madagascar periwinkle
- rose periwinkle
- rosie periwinkle
- old-maid periwinkle
- annual vinca
- running myrtle
It’s often mistaken for another plant, Vinca major, that also goes by the common names vinca and periwinkle. Let’s clear up the confusion between these two plants!
I’ll be calling Vinca major periwinkle in this discussion since the flowers are periwinkle blue.
Why Vinca? Why Periwinkle?
Vinca’s former scientific name was Vinca roseus, landing it in the same genus as periwinkle (Vinca major), which is why both plants are called vinca.
Fortunately, it’s easy to tell them apart visually and by habitat. Vinca major is a vine-like ground cover that forms dense mats. It is moisture-loving and thrives in shade.
While the flowers look similar to those of vinca, they are smaller and come in one color – a light purple-blue, a color known as periwinkle, the source for that common name.
Here’s a chart comparing the major differences between them:
| Top Common Names | Vinca, Madagascar periwinkle | Periwinkle, Vinca |
| Scientific Name | Catharanthus roseus (formerly Vinca roseus) | Vinca major |
| Flower Colors | White, red, lilac, shades of pink | Perwinkle |
| Form | Upright | Ground cover |
| Preferred Habitat | Sunny, hot, dry | Shady, moist |
Plant Lover Facts
Vinca has a long history of medicinal use and was used in both Ayurvedic and Chinese healing practices to treat diabetes, hypertension, and malaria.
In the 1950s, several vinca alkaloids were discovered that had great medical potential. They are now used in treating several types of cancer.
Did you enjoy this article?
Sign up for our weekly newsletter
where you’ll find more great info on creating &
maintaining a beautiful, carefree desert landscape.
Author Bio
Deane Alban is the creator of Southwest Gardener. She is a science writer with a bachelor’s degree in botany from the University of South Florida. Gardening is her lifelong passion. She’s been gardening in Tucson for over 16 years.
Want to see more of our
content in your search results?
Add us as a Google Preferred Source.