Our Favorite Vinca Flowers for Vibrant Color

Apply a light top dressing of compost or a slow-release granular fertilizer at planting time. Container-grown plants may need more frequent feedings with a liquid fertilizer.

Vinca

Annual vincas are also known as periwinkles and are native to semi-arid regions of Africa, which is why they do well in warmer and drier settings.

In addition to having large, brightly colored flowers, vincas also have attractive foliage and are eye-catching even when not in bloom.

Most cultivars grow upright and can reach heights up to 24 inches tall, but some cultivars have more of a trailing habit which makes them great for hanging baskets.

Vincas are sensitive plants as seedlings and do not like it wet, but can tolerate a wide range of conditions once established.

Good performers

Annual vincas are evaluated as part of the U of M flower trials and research. Located at the West Central Research and Outreach Center in Morris, Minn., the Horticulture Display Garden serves as an All-America Selections (AAS) display garden and trail grounds and provides the public an opportunity to view the newest superior performers.

The following annual vinca cultivars were rated good to excellent in our recent trials:

Growing outdoors

Vincas are versatile and perform equally well in garden beds, containers and hanging baskets. They can be planted outdoors once soil temperatures are above 60 degrees F. Plants should be spaced about 12 inches apart.

These are the requirements for choosing a site for vincas:

• Location must have full sun for 8+ hours a day.
• Soil or potting mix must be well drained. To improve drainage, compost or sand can be incorporated into heavy soils.
• Vinca prefer soils with a pH of 5.5-6 but will tolerate high pH soils.

A general-purpose fertilizer with equal amounts of nitrogen, phosphorus and potassium should be incorporated into the soil at time of planting. Vincas do not require fertilizing throughout the season as they are very light feeders. In fact, fertilizing can reduce the number of flowers produced. If you do fertilize, be sure to use it at half the recommended rate.

Vincas need regular watering but do not overwater as they are drought tolerant. Do not water late in the day so that the soil has a chance to dry out before night. Only water when the top 1-2 inches of soil are dry.

Pests and diseases are usually not an issue with this plant. Vincas are susceptible to mildew diseases but it is rarely bad enough to require treatment.

Other tips for abundant blooms and healthy plants:

• If plants are getting leggy it is usually a sign they are not getting enough sunlight.
• Removing old flowers is not necessary and will not promote new growth.
• Water the soil and not the plant to prevent mildew diseases.
• Keep the soil surface clean and weed free to prevent the growth of disease.

Starting seeds indoors

Vinca seeds can be started indoors about 10 weeks prior to the anticipated outdoor planting date. Use a growing media specifically designed for germinating seeds. Follow these guidelines for successful seed propagation:

• Lightly cover the seeds with growing media and cover with vermiculite.
• Keep the seed and media moist by using a plastic cover over the seedling tray.
• Seeds will germinate in 7-21 days at 70-75°F
• After germination, grow plants at 75°F during the day and 65-70°F at night.
• Vinca seedlings are very susceptible to damping off so let media dry out slightly between waterings.

Vinca cuttings

Vincas can be propagated via cuttings as well in about 3-4 weeks.

• Cut 4-6 inches off the top of a stem that does not have flowers.
• Remove the leaves off the bottom half of the cutting.
• Place the cutting in enough water to cover where the leaves were removed.
• Once roots begin to grow, it can be transplanted into soil.

Author: Nate Dalman, West Central Research and Outreach Center

Our Favorite Vinca Flowers for Vibrant Color

If you love the look of impatiens but need a carefree flowering annual that thrives in full sun, annual vinca is a great choice. Both plants produce an abundance of small, colorful flowers all summer long. But while most impatiens wither in hot, dry weather, vinca is undaunted by intense summer heat, making it a favorite choice for southern gardens.

And talk about variety! In addition to the usual pastel tones, you can now find yummy shades like grape, blackberry, apricot, cherry red, and tangerine—often enhanced by contrasting eyes. A wide range of growth habits are available, including trailing and dwarf forms tailor-made for containers and hanging baskets.

VINCA BASICS

Botanical name:

Common names:

Zones:

Technically a tender perennial in Zones 9 to 11, but usually grown as an annual in most climates.

Height/spread:

Typically 12 to 24 inches tall and wide, with the exception of dwarf and trailing types.

Bloom time:

Early summer until frost.

Special features:

• Attracts butterflies.
• Heat and drought tolerant.
• Needs no deadheading.
• Attractive glossy green leaves.
• Rabbit resistant.
• Pest and disease resistant.

Note: Not to be confused with common periwinkle (Vinca minor) and greater periwinkle (Vinca major), which are low-growing, evergreen perennials often used as groundcovers.

GROWING TIPS

Cora® Cascade Polka Dot vinca. Photo by Proven Winners.

Where to plant:

In full sun to part shade in well-drained soil.

When to plant:

After the ground has warmed up in the spring, typically mid-May or later in northern climates.

Growing from seed:

Sow seeds indoors 10 to 12 weeks prior to the last frost date in your area, following the instructions on the seed packet. Seeds germinate best when the soil temperatures are over 75° F. Transplant seedlings outdoors once air and soil temperatures are consistently above 65° F.

Growing in containers:

Plant in any general-purpose, well-draining potting soil. One with a slow-release fertilizer will keep your plants well fed for a month or longer and get them off to a vigorous start. If combining vincas in the same container with other annuals or perennials, choose varieties that have the same exposure and water requirements.

Planting in the garden:

Space plants far enough apart to ensure good air circulation (about 8 to 12 inches, depending on plant size at maturity). In heavy soils, work in some compost at planting time to improve aeration.

CARING FOR VINCA

Watering:

Vincas like their soil to be on the dry side, so only water when the top inch or so of the soil feels dry to the touch or when rainfall is insufficient to supply an inch of water per week. To prevent leaf spot and fungal diseases, avoid overhead watering or water your plants early in the morning so the foliage has plenty of time to dry before nightfall.

Fertilizing:

Apply a light top dressing of compost or a slow-release granular fertilizer at planting time. Container-grown plants may need more frequent feedings with a liquid fertilizer.

Pruning:

Although pruning is unnecessary, you can pinch plants back if you want a fuller appearance. Flowers are self-cleaning, sparing you the chore of deadheading.

Pests and problems:

Annual vinca is invincible to most pests, but it can succumb to stem and root rot caused by Phytophthora—a soil- and water-borne fungal-like microorganism. The best preventive measures are to avoid overwatering and provide good drainage. These plants are also susceptible to leaf spot diseases, with the best defense being good air circulation and to water them in the morning. Another way to avoid fungal problems is to plant one of the newer disease-resistant cultivars, such as the Cora® series.