annual vinca-bright color- loves the midsummer heat

July 29, 2021

Easy Care Color For Your Garden

Do you have a place for all-day everyday color, and over a very long blooming season? Do you need a boost for that sometimes dull period in the garden when the spring burst of bulbs is over and summer blooms are not here? Annual Vinca-Catharanthus roseus blooms constantly from early summer through the fall. Vinca is an unusually resilient plant that will provide bright color and loves the mid-summer heat.

The annual Vinca provides bright summer color, low maintenance, tolerance of poor soil, and drought-resistant! On hot days you can look at them from a shady hammock. There is not much work to do. The blossoms are profuse and come in many colors and even pattern. Annual Vinca is not the perennial ground cover also called vinca or periwinkle.

This is Catharanthus roseus, it is taller and you will often see the characteristic colored “eye.” The eye is often in different colors creating a patterned effect.

Africa’s Gift-Loves The Heat

map of Madagascar

Some people call vinca “Africa’s gift to the world” because it is beautiful, useful, easy to live with, and has medicinal benefits too!

Discovered on Madagascar, a challenging climate for many plants, and the world’s 4th largest island. it was first named by Linnaeus and later reclassified to its current genus and species in the 19th century..

Don’t Be Fooled By Confusing Names

This is one of many plants with a confusing number of names that are used by multiple plants. This plant is Catharanthus roseus it is in the dogbane family and it’s called vinca, periwinkle, old maid, bright eyes, it goes on.

Our annual vinca is commonly confused with Vinca minor, also called periwinkle. This one is the blue-flowered, periwinkle ground cover that is great for controlling steep slopes. Same family (Apocynaceae-dogbane), different genus. When a plant has a specific epithet or species called minor you can expect it to be a smaller relative. It is, however, only the names that are confusing, the plants do not look similar.

This is Vinca minor or periwinkle. Note the pinwheel-shaped flower, the characteristic shade of blue, and the densely packed, bright green leaves. The plant is also the lowest growing of the three and is the only perennial in the group.

In the hot summer, this mounding annual offers a bold and vivid display just when other color plants are drooping. They are not flawless but they are easy and fun to see in the garden. In our South Florida garden, they last longer than a year. If your summers get hot and you need color for a bright, sunny spot, this plant will bloom vigorously when many other options will fail.

Is Vinca-Catharanthus roseus An Annual Or A Perrenial?

Like a lot of the plants we call annual and often treat as such our vinca is actually a tropical perennial, unable to accept cold. In zones 9-11 it is a shorter-lived perennial. In colder climates-zones 2-8.

Update

This is a low-maintenance source of color for the garden. The photo is an interesting comment on “low” maintenance. We planted Vinca in a hanging basket which we enjoyed. Seeds dropped to the ground. Too indolent to pick up the tiny plants I left them. This large healthy patch of blooms is the result!

vinca plants growing from seed

This is what happens when the seeds drop.

How Can I use Vinca?

Remember, that flowering Vinca originates in hot, arid Madagasgar. Color choices are many, look for pink, white, purple, red, magenta, lavender. Some are bicolor, some called polka dot due to a center of a second bright color. These are old cultivars, around since the 1920s and their popularity encourages the creation of new varieties. Look out for new ones.

Size and Shape-How Far Can Annual Vinca Spread?

How to use them:

There are two forms of this plant, Upright; about 15″ high and wide. The second is Trailing, some varieties can reach 36″ wide, they are lower than the upright version. The trailing version is superior in hanging baskets and containers. On the ground, it covers a considerable territory with color, and for a modest price.

  • Beds
  • Borders
  • Containers
  • Hanging baskets
  • Window boxes
  • To create a bright ground line in front of a wall or hedge

Where And When Can I Use Vinca?

Plant them in spring after you expect the soil temperature to be 70 degrees. A cooking thermometer works just fine to test your soil. In colder climates, this would be about the first of May. We can plant them most of the year in South Florida. (We would avoid January and February to be cautious in zone 10.) The best way to have problems is to have them in the ground over a cold wet spring. It won’t guarantee failure but it is a risk.

They are suitable for full sun or part sun. Some people prefer one position over another. In our experience in gardens in several geographical locations, both have worked. You know your own microclimates.

Vinca is low maintenance plant, the one critical feature to provide is good drainage. If you think your soil drains poorly you can amend it with organic matter, peat, sand. This is how to measure your drainage. This is about different soil types and how they can be improved.

Vinca vs Impatiens

Sometimes these two are confused. They are similar in size and flower shape. The leaves are similar and they serve the same purpose. The important differences are these: Vinca thrives in heat, hot and dry, or hot and humid. Impatiens will tend to wilt after extended periods of heat. Rabbits find the impatiens tasty. Not so the Vinca. Vinca leaves are smooth on the edge. Impatiens have a leaf with a serrated edge.

Here is Impatiens walleriana, it is available in a wide variety of interesting and often subtle colors and the leaves of most are glossy. Note the serrated edge of the foliage.

While Vinca has a nice variety of colors to offer, Impatiens have more. We in zone 10b like to use impatiens in the winter and enjoy them as long as we can in summer. The Vinca can last several years. In a zone a little north of ours we could keep Impatiens for several years. Not here.

Some Helpful Varieties Of Vinca

As a popular plant, vinca includes many cultivars. Cultivars are man-made varieties of plants. In plants like vinca that are easy to grow, you can expect to see a pretty steady stream of new varieties.

Here are some examples. These are branded trade names given to the plants. You will see them labeled in the garden center. In South Florida, I’ll be seeing lots of them all summer and winter. In colder climates look for them in spring.

  • Cora Apricot
  • Cora Red
  • Cora White
  • Cora Cascade Magenta
  • Cora Cascade Strawberry
  • Soiree Double White
  • Soiree Kawaii Coral
  • Soiree Kawaii Lavender
  • Soiree Kawaii Pink Peppermint
  • Soiree Kawaii Pink
  • Valiant Apricot
  • Valiant Burgundy
  • Valiant Lilac
  • Valiant Orchid
  • Cataranthus roseus Pacific, this series has several colors and is tall. about 2′ if you need height this might be the one for you.

How To Plant Vinca

You will buy smaller plants, ready to grow in the ground. Dig a hole about twice the size of your new plant and as deep as the pot. You can lighten your soil with a potting mixture. Carefully take the plant from the pot. You can cut the pot or squeeze it to cautiously remove the young plant. Annuals normally do not need the roots separated. You can gently massage the root area to loosen the root. Plant in the ground or container with the top of the plant slightly above the soil line. Water the plants as you put them in the ground.

Vinca is drought-resistant once established. Put your finger in the ground, when it is dry about an inch down, add water. Add water-soluble fertilizer to the plants monthly during the bloom period. Follow the instructions on the fertilizer box.

Always take steps to ensure good drainage. Containers tend to produce very good drainage. In hanging, baskets make sure that some large pieces of mulch or other draining materials are near the bottom to ensure drainage. Hanging baskets need to be watered every day in summer. Water until it drains out the bottom. How to choose potting soil might be helpful.

The new cultivars of Vinca should not need deadheading.

Pollinators And Wildlife

Butterflies are attracted to Vinca and fortunately, deer and rabbits are not. In our community, we are favored by both animals and they do ignore vinca.

Pests And Diseases

Vinca, popular for decades, developed a problem with fungus a few years ago. It became a serious issue and eventually, new cultivars, resistant to disease were developed. Two varieties that are resistant are Cara and Nirvana. Each is available in both varieties, upright and cascading. The cascading variety covers 36″ with large blossoms in many colors. Colors in Cara include Cherry, Lilac, Magenta. Peach, Periwinkle, and Polka dot.

The problem is aerial Phytophthora fungus. It exists in soil and can splash on the plant in rain or from overhead watering. It is the only serious problem with Vinca and the solution seems to me to plant only varieties resistant to the fungus.

It is a very good solution but not absolutely perfect. The signs of the problem are black spots that look like sooty mold. If you see it remove the plant and destroy it including the roots. Talk to your local garden center or your county agricultural extension agent. There may be other varieties desirable in your local area.

Good Companion Plants For Vinca

Pair vinca with other plants that like the same conditions. I am looking at an image consisting of blue salvia in the back, then magenta vinca, and zinnia. An attractive and simple display. Other choices are moss rose, lantana, million bells, and sweet potato vines, or angelonia.

Often Vinca includes a center dot of a color different than the rest of the flower. It can be fun to match that dot color to that of another flower. Perhaps a burgundy dot with burgundy coleus?

Look in your garden center, this simple flower with sometimes two or three colors will give you some good ideas for planters or beds at your house.