New Guinea impatiens are popular annual bedding plants for providing bright color in shady areas. The plant will grow in deep shade where many flowers will not, and will continue to reliably produce bright flowers from spring until fall. The flowers prefer moist soil and will seem to collapse when they need watering. Impatiens will recover just as dramatically when given water.
New Guinea impatiens were introduced into the United States for commercial sale in 1972. The plants are native to New Guinea, where they grow along boggy river banks in full shade. The plants were collected by the USDA in 1970. Several species of impatiens were collected, but the scientists discovering them thought that each flower was a distinct species. Scientists have since discovered that all the flowers are from the same diverse family.
There are two types of impatiens on the market, New Guinea impatiens and common garden impatiens. New Guinea impatiens require similar care to common garden impatiens, but New Guinea impatiens will tolerate more sun than common garden impatiens. The New Guinea variety is also larger in size and has brilliantly marked foliage.
New Guinea impatiens initially received a bad reputation as a bedding plant because the first bedding plants were sold as plants for full sun. While the plants will do well in partial sun, they prefer morning sun and evening shade. Plants that are not grown under these conditions often fail to thrive. Recent hybrid varieties of New Guinea impatiens have been developed that survive better in full sun if they are given enough water.
New Guinea impatiens are often grown in patio containers or hanging baskets. In hanging baskets, the plants are shaded by the eaves of a home. The plants may also be planted in the ground beneath trees and shrubs to fill in sparse, shady areas where other plants won't grow.
New Guinea impatiens should be grown in well-drained soil in the ground. In containers, select a potting mix that is heavy in bark and peat moss. The pH of soil for New Guinea impatiens should be slightly acidic, between 5.5 and 6.2. Potted impatiens should be watered thoroughly and deeply. Fill the container with water to the brim and then drain from the soil. Allow the soil to dry between watering. New Guinea impatiens will appear to wilt and collapse when they need watering, but will spring back within minutes of being watered.