Giant impatiens add a striking visual presence to any garden, admired for their vibrant blooms and robust foliage. These ornamental plants are a popular choice, offering an impressive display and flourishing in various settings.
What Are Giant Impatiens?
The term “giant impatiens” refers to Impatiens niamniamensis (Congo Cockatoo or Parrot Plant), and larger cultivars of New Guinea Impatiens (Impatiens hawkeri) and SunPatiens. Impatiens niamniamensis, native to tropical Africa, is an evergreen perennial with erect, succulent brown stems and spirally arranged, ovate leaves. Its distinctive flowers resemble a parrot’s beak or cornucopia, featuring vibrant combinations of greenish-yellow, orange, red, crimson, or purple, often appearing as scarlet red and yellow with a lime green hood. This species reaches 2 to 4 feet tall and can bloom year-round in mild climates.
New Guinea Impatiens are sturdier and bushier, producing larger blooms than traditional impatiens. Their foliage varies from dark green to burgundy or variegated, complementing colorful flowers in shades of orange, pink, red, white, and purple. SunPatiens are modern hybrids, bred to tolerate more sun, heat, and humidity. These vigorous plants offer continuous blooms and grow between 14 and 42 inches tall and 14 to 36 inches wide.
Optimal Growing Conditions
Light
Optimal light conditions vary, but most giant impatiens thrive with protection from intense, direct sun. Impatiens niamniamensis prefers bright, indirect light or partial shade, benefiting from morning sun or tree-filtered light while shielded from harsh afternoon sun. In very warm climates, full shade is recommended to prevent scorching. New Guinea Impatiens prefer partial sun, receiving 3 to 6 hours of indirect or dappled sunlight daily, often favoring morning sun with afternoon shade. Excessive sun can lead to leaf burn and reduced flowering, though some cultivars tolerate more sun. SunPatiens are bred to flourish in full sun to partial shade, resilient to high heat and humidity, with flowering undiminished by filtered light or limited direct sun exposure.
Soil
All giant impatiens benefit from well-draining soil rich in organic matter. Loamy soil is ideal, retaining moisture without becoming waterlogged. Amendments like peat, perlite, or compost enhance drainage and aeration. A slightly acidic to neutral pH is preferred: Impatiens niamniamensis thrives around pH 6.0, New Guinea Impatiens favor 6.0-6.5, and SunPatiens do well within 5.8 to 7.0.
Watering
Consistent moisture is important for giant impatiens; keep the soil evenly moist but never saturated. While plants may wilt if the soil dries out, they typically recover once watered. Regular watering is needed, and checking the soil to prevent sogginess is key to preventing root issues. Drip irrigation is an effective method for maintaining consistent soil moisture without overwatering, especially during establishment.
Temperature and Humidity
Giant impatiens thrive in moderate to warm temperatures and require high humidity. Impatiens niamniamensis prefers 50-80°F (10-27°C) and tolerates temperatures as low as 35°F (2°C), but is sensitive to frost. This species benefits from high humidity, ideally around 80%, or at least 40% indoors. New Guinea Impatiens grow best with daytime temperatures between 70-85°F and nighttime temperatures between 55-65°F; they are sensitive to cold, with growth slowing below 45°F. SunPatiens are more tolerant of heat and humidity, but cooler night temperatures below 58°F (13°C) can restrict their growth.
Fertilizing
Regular fertilization supports growth and flowering in giant impatiens. For Impatiens niamniamensis, apply a balanced 10-10-10 fertilizer every 4 to 6 weeks during the active growing season, or a general-purpose fertilizer every 2 to 3 months. New Guinea Impatiens are heavy feeders, benefiting from monthly fertilization to encourage blooms. SunPatiens are lighter feeders; a nitrate-based liquid fertilizer at 75 to 100 ppm every 3 to 4 weeks or a slow-release fertilizer at half the typical rate is sufficient.
Common Issues and Solutions
Giant impatiens can face common challenges, including pests and environmental stressors. Pests like aphids, spider mites, mealy bugs, and scale can infest these plants, requiring prompt treatment. Environmental issues include leaf scorch from too much direct sun. Wilting, a sign of dry soil, indicates the plant needs watering. Yellowing leaves can signal insufficient watering or a need for more nutrients. Overwatering can lead to root rot, particularly in poorly draining soils, though SunPatiens show some resistance to downy mildew.
Pruning and Ongoing Care
Pruning is important for maintaining the health and appearance of giant impatiens. Regular trimming encourages bushier growth and prevents plants from becoming leggy. Removing leggy stems also improves air circulation. For types like New Guinea Impatiens, deadheading spent flowers encourages new blooms throughout the growing season.
For Impatiens niamniamensis, pruning is not always necessary unless shaping is desired, but tip pruning encourages more side shoots and a fuller form. If the plant appears leggy, cutting back about 3 to 4 inches (8-10 cm) can rejuvenate it. Beyond pruning, ongoing care involves regular inspection for pests or diseases. Maintaining high humidity, especially for Impatiens niamniamensis, can be achieved through regular misting or by placing the plant on a humidity tray. Applying mulch around the base helps retain soil moisture and regulate soil temperature.