Pansies are members of the Viola genus, a taxon of flowering plants in the violet family Violaceae, with around 400–500 species distributed around the world. Viola, was named by Greeks in the 4th century BCE and was cultivated for its medicinal properties. Pansy or garden pansy is the common name for diverse cultivated plants raised for their flowers, Viola tricolor hortensis or Viola x wittrockiana, characterized by five, almost heart-shaped, overlapping petals and a wide diversity of possible colors (yellow, blue, red, orange, white, etc.), including bicolored flowers.
The name pansy is derived from the French word pensée, meaning “thought,” and was so named because the flower resembles a human face; in August it nods forward as if deep in thought.
More than 250 cultivars of pansies have been developed, such as “Majestic Giant,” “Imperial,” “Universal,” “Crystal Bowl,” “Bingo,” and “Karma”.
Pansies are generally very cold hardy plants, surviving freezing even during their blooming period. Plants grow well in sunny or partially sunny positions in well drained soils. Growing pansies are commonly seen in late fall and early spring in more northern areas of the United States, while in subtropical areas, pansies bloom throughout the winter. Pansies are cold-hardy and need a frost cover only when temperatures dip into the low 20s.
According to the USDA NASS Census of Horticulture 2014, pansies in the US have a wholesale value of $159M and are the second highest in terms of units (containers & flats) sold with more than 56 million produced annually.
Main Disease & Pest Problems
Pansies have several main disease problems including leaf spots (caused by Centrospora, Alternaria and Ramularia fungi), anthracnose, scab, powdery mildew, downy mildew and cucumber mosaic virus.
Pansies have a wide variety of pests such as aphids (which vectors cucumber mosaic virus), fungus gnats, shoreflies, western flower thrips, and cater pillars, snails/slugs, whiteflies and two-spotted spider-mites cause issues.
Most of the research IR-4 has sponsored has been related to crop safety (16 trials with 8 products), but we have screened new actives and products with pansy for effective management of Black Root Rot (Thielaviopsis basicola), Myrothecium Leaf Spot (Myrothecium roridum) and Phytophtora nicotianae root rot.
USDA-NASS Census of Horticulture (2014).
Ely Vea, IR-4 Environmental Horticulture Program Assistant Manager, and Cristi Palmer, IR-4 Environmental Horticulture Program Manager