By Julie Christensen
Impatiens flowers (often called “impatients”) have long been the most popular bedding plant in the U.S. for several reasons. The plants have an attractive mounding form with glossy leaves and delicate flowers. They tolerate full shade, where most other flowering plants won’t grow, and they’re fairly easy to maintain. Most varieties are self-cleaning, meaning that you don’t need to deadhead them.
Common impatiens (Impatiens walleriana) are widely available at garden centers. These annual plants come in a variety of colors, including red, white, pink, coral or multicolor. The classic variety has single flowers, but new varieties have double petals and sometimes even resemble tiny roses. However, common impatiens have been plagued by downy mildew in recent years — see below for more information.
New Guinea impatiens (Impatiens hawker) were introduced in 1970 from New Guinea. These annual plants have larger, bolder flowers and brighter leaves than common impatiens. They’re beautiful in their own right, but need a bit more maintenance than their humble cousins. They don’t tolerate cool night temperatures and need consistently moist, but not soggy, soil to grow well.
Rose balsam (Impatiens balsamina), also known as “touch me not,” was once widely grown, but has fallen out of favor in recent years. These plants grow up to 2 feet tall and have lovely flowers that resemble small camellias or roses. Once the blooms fade, long pods appear. Dense foliage partially obscures the flowers, which is one reason they’re grown less frequently than other varieties.
All species of impatiens have similar growing requirements. Impatiens are tender, annual plants that don’t tolerate frost. Plant them outdoors only after the last expected frost. Choose a location that gets 2-4 hours of sunlight daily for best flowering. A location with filtered morning sun and afternoon shade is ideal. Although impatiens will grow in full shade, they’ll grow taller and they won’t bloom as much.
Most people grow impatiens from nursery bedding plants, but you can grow them from seed, as well. Start them indoors 8 to 10 weeks before the last expected frost. Plant the seeds 1/8 inch deep in sterile potting soil and keep the soil moist and warm. Plant transplants outdoors after the last frost, when they stand 3-4 inches tall. Space them 4 inches apart. Amend the flower bed with compost and dig in a 10-10-10 granular, slow-release fertilizer at a rate of ½ cup per 100 square feet of garden soil. This fertilizer should provide enough nutrients for the entire growing season.
Impatienses also make beautiful potted plants. Plant them in hanging baskets, pots or window containers. Use a sterile, lightweight potting mix that contains perlite to retain moisture.
Check the soil frequently throughout the growing season. Water bedding plants at least once per week during hot weather. Drought will cause the plants to become leggy and produce fewer blooms. Make sure the soil is lightly moist, but not soggy. Water impatiens growing in baskets as often as once per day during hot weather, since these plants dry out more quickly than those grown in the ground. Fertilize container plants every two weeks with a dilute solution of 10-10-10 water soluble fertilizer.
Pests and Disease
In recent years, downy mildew has become a big problem for impatiens. The first signs are yellowing leaves, followed by curling leaves and a white fuzzy growth. New Guinea impatiens are less susceptible than other varieties. Once it strikes, downy mildew is very difficult to control. Remove any diseased plants immediately and clean up all falling leaves. Use soaker hoses to keep the leaves dry and space the plants so air circulates freely. If you’ve had a problem with the disease in the past, choose a different location for planting impatiens. You may have to choose other annual bedding plants if the disease becomes severe.
To learn more, visit the following links:
Impatiens from Clemson University
Alternatives to Impatiens from Michigan State University
Caring for Impatiens on YouTube.
Julie Christensen learned about gardening on her grandfather’s farm and mother’s vegetable garden in southern Idaho. Today, she lives and gardens on the high plains of Colorado. When she’s not digging in the dirt, Julie writes about food, education, parenting and gardening.