Impatiens hawkeri

These succulent, branched perennial herbs grow up to 15 inches tall, mounding with lower leaves up off the ground. New Guinea Impatiens tolerate full sun, but are a water guzzler and tend to look wilted when heat loads are high and water is less plentiful, making this plant have a low drought tolerance. These plants tend to be larger with larger flowers than on standard Impatiens. The flowers will bloom from spring to early fall. Gardeners must be careful when watering the plant, however, because over watering can cause rot. This plant is a herbaceous perennial, but most often used as an annual in planters, hanging baskets, containers, around trees in shaded areas, and in bedding. It has multiple cultivars and is often confused with sultanas, although the leaves are thicker and leaves in the mound are raised above the ground. The genus name comes from the Latin impatiens meaning impatient and refers to the sudden seed discharge from the ripe pods. The species name honors Lt. Hawker of the British Royal Navy who collected the plant in Papua, New Guinea in 1884.

This plant performs best in partial shade with well-drained, moist soils supplemented with organic material. The plant tolerates full shade and should be protected from full summer sun. Seeds are sown in March under glass and germinate at 70 to 75 degrees F. Plant out in May. As the plant matures, you can pinch back the stems to encourage branching and discourage the plant from becoming leggy. Because the plant does not do well outdoors at temperatures below 40 degrees, most gardeners treat it as an annual and purchase new plants each spring. However, you can trim the plant back and bring indoors at a sunny window. This plant is resistant to Downy Mildew. 

New Guinea impatiens encompass a large number of different cultivars some of which have been introduced as part of named series.

Quick ID Hints:

• Flowers have conspicuous, elongated spur.
• Lateral sepals are suborbicular, broad, and acuminate.
• Leaves have stalked glands on teeth rising above the leaf plane.

Diseases, Insect Pests, and Other Plant Problems:

No known insect or disease problems. Possible problems include impatiens necrotic spot virus, fungal blights, powdery mildew, and rots. Potential insect problems include aphids, mealybugs, thrips, whitefly, slugs and snails, and spider mites.

VIDEO Created by Elisabeth Meyer for "Annuals, Perennials, Vines, and Groundcovers" a plant identification course offered in partnership with Longwood Gardens.