When was impatiens first introduced in Toronto, and when did it reach the peak of its popularity?
Common Impatiens or Impatiens walleriana, was once the number 1 selling annual in North America during the early 2000s. It was the go to for many gardeners to brighten shady areas and containers
Traditional impatiens was also known as busy Lizzie (British Isles), balsam, sultana, or simply impatiens, is a species of the genus Impatiens, native to eastern Africa from Kenya to Mozambique. The plant was originally named Impatiens sultanii, to honour the Sultan of Zanzibar. The Latin specific epithet walleriana honours a British missionary, Horace Waller (1833–1896). The name is derived from Latin in reference to the way they shoot out seeds when the seed pods open.
Claude Hope, an American horticulturalist and seed distributor, discovered the original plant in Costa Rica. In the 1960’s, through hybridizing and breeding, Mr. Hope changed Impatiens walleriana from a gangly plant to the compact shade loving annual we know today.
Impatiens steadily grew in popularity until 2013, when widespread outbreaks of Downy Mildew, a disease caused by the fungus-like water mold Plasmopara obducens, destroyed many plants. There was no cure for the disease. Nurseries stopped growing Impatiens walleriana. New Guinea or Sunshine impatiens was suggested as an alternative.
Beginning in 2019 disease resistant varieties in a variety of colours became available and are gradually making their way to garden nurseries. To learn more about these new annuals see the following:
Toronto Master Gardeners previously have answered questions regarding Impatiens and Downy Mildew. I have included a link to one of these below: