COLUMBIA, Mo. – If there’s a plant that deserves the title of “flower for all seasons,” it is the pansy, says University of Missouri Extension horticulturist David Trinklein.

At any given time in North America, you will find pansies blooming prolifically somewhere.

This cool-loving garden flower flourishes in winter in far southern states and in summer in northern regions. Midwesterners enjoy pansy’s unique palette of colors and delicate fragrance in spring and fall.

Late March and early September are ideal months to plant them in Missouri for color that extends for many weeks.

Many confuse pansy with its more petite relative, the viola. Both have flowers with five petals. However, pansy has four petals pointing up and one pointing down. In contrast, three of viola’s petals point up and two point down. Its flowers also are usually smaller than those of the pansy.

Pansies and violas share a common ancestry. Greeks grew violas mostly for medicinal purposes as early as the fourth century B.C. A watchful gardener noticed that a particular viola flourished in sunny, alpine meadows. This strain of viola received the common name of wild pansy.

In the early 1800s, English nobleman Lord Gambier and his gardener, William Thompson, crossed species of the genus Viola. These crosses resulted  in plants that produced larger flowers of unusual colors and color combinations.

History credits Thompson with the cross that resulted in the now-familiar Viola x wittrockiana. Its flowers burst with huge blocks of color or faces on the lower petals.

By the mid-1800s, Europeans had bred pansies and developed hybrids with greater plant vigor. The flowers of these hybrids had no dark blocks or lines. Thus, “clear” pansies got their start.

Popularity of the pansy skyrocketed in North America. A 19th-century seed catalog described pansy as "the most popular of all flowers grown from seed,” with sales exceeding 100,000 packets a year.

Over the past several decades, breeders have produced pansies with new colors, including shades of pink, rose or orange, and flowers with unusual bicolor designs. Given pansy’s enduring popularity, the improvement of this charming little plant is far from over, Trinklein said.

Most gardeners choose to plant pansies sold in bedding plant packs. Choose pest-free stocky plants with healthy leaves and unopened buds, he said.

Pansies enjoy cool weather and abundant sunshine. Unfortunately, in the Midwest this combination of conditions happens only in spring and fall.

For best results, Midwestern gardeners should choose an exposure of morning sun followed by afternoon shade, Trinklein said. Although pansy grows as an annual in Missouri, fall-planted pansies often survive winters and bloom in late winter or very early spring when temperatures rise.

Pansies have fine and delicate root systems. Plant them in porous soil enriched with organic matter to promote good soil aeration and proper water retention. Incorporate 3-4 inches of well-decomposed organic matter as a best management practice. Add pre-plant fertilizer as needed.

Space pansies about 6-10 inches apart and add 1-2 inches of water at the base of the plant. Do not allow soil to dry. Add water-soluble fertilizer as according to label directions.

Pansies grow relatively disease- and pest-free. Yellow leaves often indicate root rot, usually caused by overwatering. A white, powdery substance on leaves and stems indicates powdery mildew. Choose a location with good air circulation to prevent this.

Slugs and snails sometimes attack pansies. These nocturnal feeders produce gaping holes in the leaves. Control slugs and snails with poisonous baits.

“The lack of gardening activity during winter can be a bit depressive, especially to avid gardeners,” Trinklein said. Because pansies can be planted very early, they bring an end to the winter doldrums. “Therefore, it might be concluded that pansies, with their cheerful, ‘smiling’ flowers, are as therapeutic for our inner being as they are beautiful to our eyes.”

Photo available for this release:

https://extension.missouri.edu/media/wysiwyg/Extensiondata/NewsAdmin/Photos/stock/pansyCoolWave.jpg
Cool Wave yellow trailing pansy. Courtesy Ball Horticultural Company.