Impatiens sodenii (Shrub Balsam) - A frost tender shrub (often treated as a perennial) that is usually listed to 5 to 6 feet tall but when very happy can grow as large as 8+ feet tall by as wide but is usually seen about half this size and often kept more narrowly upright. It has a woody base and semi-succulent green stems bearing 8-inch-long dark green leaves in whorls. At the tips of the stems are the showy 2 1/2 wide pink flowers with slender spurs. The flowers bloom throughout the year at first emerging pale pink and fading to nearly white with flowers darkest in the cooler months.
This large Impatiens does best in a well-drained soil in light shade or morning sun, but at the coast it will grow in full sun. It grows rapidly when watered regularly in warmer gardens to occasionally along the coast, where with a little protection it is tolerant of seaside conditions. Although it is hardy to only about 30 degrees F, limiting it to the nearly frost-free areas (USDA 10-11), plants damaged by a frost will often resprout at the base and seed can perpetuate the plant as an annual in even colder climates. Prune annually after frost danger is past to shape and remove cold-damaged stems then only tip prune the rest of the year; avoid cutting back hard as this discourages flowering. Trim out the side branches if planted in a narrow space to keep plant more upright.
Impatiens sodenii is native to the tropical East African highlands between 3,000 and 8,000 ft. elevation in Kenya and Tanzania. The name for the genus is from the Latin word 'impatientem' which means "unable to wait patiently" or "desiring immediate action" in reference to the sudden dehiscence of the of the fruit capsules. The common name "touch-me-not" sometimes used for plants in the genus is in reference what is sometimes called an explosive dehiscence of seed. The specific epithet honors Julius, Freiherr von Soden (1846-1921), who was governor of several German colonies in Africa and founder of the Central Botanical Office for the German Colonies. This plant has long been known by the name Impatiens oliveri, a name honoring the British botanist Daniel Oliver (1830-1916) and it is also commonly called Oliver's Touch-Me-Not and Poor Man's Rhododendron.
This plant was the recipient of the Royal Horticultural Society's Award of Garden Merit in 2012. It has long been cultivated in California as evidenced of it being documented growing in the San Diego garden of the American botanist, horticulturist and landscape architect Kate Sessions (the "mother of Balboa Park") in 1906. We have grown this great ornamental plant continually since 1997 and we also grow the white flowering cultivar Impatiens sodenii 'Madonna' and the red stemmed and dark pink flowering Impatiens sodenii 'Robert the Red'.
The information about Impatiens sodenii displayed on this web page is based on our research conducted in the nursery's horticultural library and from reliable online resources. We also include observations made about it as it grows in our nursery gardens and other gardens we have visited, as well how the crops have performed in containers in our nursery field. We will also incorporate comments we receive from others and welcome hearing from anyone with additional information, particularly if they can share cultural information that would aid others in growing this plant. |