Ornamental · Balsaminaceae
New Guinea Impatiens
Impatiens hawkeri
Set it in rich, damp soil and soft shade, and New Guinea impatiens carries color from spring through to frost.
Partial shade
59–81°F · 15–27°C
85–110 days
USDA 10–12
Overview
New Guinea impatiens brings a season of big, bright flowers to the parts of a home that need lifting, from a shaded terrace to the pot that greets guests at the door. It comes from the islands north of Australia as a tender perennial, though most rooms and gardens keep it as a garden annual, refreshed each spring. Its neat, mounded shape settles easily into a bed, a border, or a grouping of containers, holding its lines without sprawl.
This is the impatiens that goes where the older bedding type could not. It takes more sun, so it opens up brighter corners of a patio, and it steps past the downy mildew that once thinned so many summer displays. Where the setting is fully exposed, the interspecific SunPatiens hybrids carry the same look through full sun and real summer heat.
Its charm is how little it asks of a daily routine. Keep the soil damp but never soggy, feed it through the season, and it flowers without a break from spring to the first frost, an easy anchor for a planting that has to look good for months. Let it go dry in the heat and the leaves stipple while the flowers fade fast, so a steady hand with the watering can keeps the whole scene fresh.
Care
The short version: set it in partial shade with rich, well-drained soil kept evenly moist, offer a balanced feed every couple of weeks, and pinch off spent blooms so the display keeps its color.
Light
Give it partial shade, above all where summers turn hot, and it rewards the shaded corners of a patio or porch. It takes more sun than common impatiens, opening up brighter spots, yet a bright afternoon without enough water leaves the plants stressed and the leaves stippled.
Water
Keep the soil evenly moist throughout, never soggy and never bone dry, and the planting holds its bloom. The sunnier the position, the thirstier the plant, so a spot in full light or a container works its way into the daily watering round. Good drainage is what keeps that steady moisture from becoming root rot.
Soil
Plant it in rich, well-drained soil worked through with plenty of organic matter. The mix should hold moisture without staying wet, since these plants favor damp roots yet decline in standing water.
Temperature
It shows best between 59°F and 81°F (15°C to 27°C) and has no tolerance for frost. A cold snap ends the season for it, the reason it plays the role of an annual outside the warmest zones.
Humidity
Ordinary room and garden humidity suits it, so there is no figure to chase. Steady moisture at the roots counts for far more than the air, and dry heat is what invites spider mites into a display.
Feeding
These are heavy feeders, above all in containers where a season of bloom draws on the soil. A balanced liquid fertilizer every couple of weeks through the growing season keeps the flowers coming and the foliage full and lush.
Pruning
There is no hard pruning to schedule. Deadhead the spent flowers to keep fresh ones opening, and pinch off any damaged or diseased growth as you pass, which keeps the planting looking cared for.
Size & spacing
Plants stand 6 to 20 inches (15 to 50 cm) tall and spread 12 to 24 inches (30 to 60 cm) wide in a tidy mound that suits both beds and pots. Leave a little room between them so air moves through and the leaves dry after rain.
When to plant
New Guinea impatiens cannot take frost, so the calendar for planting follows the cold. Move it into its spot only once the last frost has passed and nights hold above 50°F (10°C), and from there it carries color from spring right through to the first frost in fall.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: 8 to 10 weeks before last spring frost (seed strains only)
- Plant: After last frost when soil and night temperatures stay above 50°F (10°C)
- Harvest: Spring through fall until frost
Hardiness
USDA hardiness zones: 10–12
Temperature: down to -1°C
Troubleshooting
Most of what goes wrong with New Guinea impatiens comes down to water and air, either too much lingering at the roots or too little reaching the leaves in the heat. The foliage and flowers show it early, so a quick look now and then lets you set things right before a planting loses its polish. Match what you see below, then act while it still keeps the display looking its best.
Drooping, collapsing plants in damp soil
A container left standing in water tends toward root rot, so a plant that droops in soggy soil is asking for less water, not more. Ease it from the pot and check the roots, which turn brown and soft rather than white and firm. Scale back the watering, correct the drainage or move it to a looser mix, and set aside anything past saving so the rest of the arrangement stays fresh.
Fix:
- Reduce watering frequency
- Improve soil drainage or repot
- Remove severely affected plants
Freckled, yellowing leaves wrapped in faint webbing
A container that has been sitting in a hot, dry corner often picks up spider mites, which dull the display before you notice why. Turn the leaves over to find the tiny specks and thin webbing, or tap one above white paper and watch for movement. A rinse, soil kept moist to relieve the strain, and insecticidal soap or horticultural oil on the undersides brings the planting back to form.
Fix:
- Rinse foliage with water
- Keep soil moist and reduce heat/drought stress
- Apply insecticidal soap or horticultural oil to leaf undersides
Fuzzy gray mold on flowers and leaves
A crowded pot in cool, damp, still air is where gray mold settles, taking the fading blooms first and dimming the whole arrangement. Lift out the spoiled flowers and leaves to keep the look clean, give the planting room so the air can move, and water at the base rather than across the top. The display holds its polish once the air circulates.
Fix:
- Remove and discard affected plant parts
- Improve air circulation and spacing
- Water at the base and avoid wetting foliage
Kinked new growth, sticky leaves, streaked petals
Aphids and thrips go for the fresh growth and the flowers, the very parts that carry a planting's finish. Look over the shoot tips and blooms for small insects, and note the silvery streaks and scarring that thrips leave on the petals. A firm rinse, a pass of insecticidal soap, and trimming away the worst growth restores the clean lines of the display.
Fix:
- Rinse plants with water
- Apply insecticidal soap
- Remove heavily infested growth
Toxicity
For a home shared with pets and children, this one is easy: New Guinea impatiens is non-toxic through and through. The ASPCA lists impatiens as safe for cats, dogs, and horses, and a stray nibble poses no threat to the other animals about the house. Place it wherever it looks best, with nothing to weigh against the choice.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
Cats can share the room with it, since a curious nibble on a leaf or flower will not poison them.
Dogs None
Dogs are welcome nearby as well, because the ASPCA lists impatiens as non-toxic, so a chewed leaf is nothing to mind.
Horses Safe
Horses come to no harm around it, and a mouthful of the plant will not upset them.
Rabbits Safe
Rabbits can browse the leaves and blooms with nothing to fear.
Livestock Safe
Cattle, goats, and sheep can keep company with it, since the plant holds nothing to trouble them.
Birds Safe
Backyard and pet birds are at no risk, and a pecked leaf or flower does them no harm.
People Safe
It belongs comfortably in rooms with children; though it is not grown to eat, a leaf in a small mouth will not poison anyone.
Varieties
New Guinea impatiens arrives as named series rather than a long list of standalone names, and a handful appear again and again in the trade. These are the ones to keep in mind when planning a look.
'SunPatiens'
An interspecific hybrid group made for open, sunny, heat-soaked spots, with robust growth that carries through rough spells.
'Divine'
A seed-raised series, a quiet rarity in a group that is otherwise carried on through cuttings.
'Celebration'
A cuttings-raised series offering generous blooms in a wide sweep of shades.
'Sonic'
A cuttings series prized for its early, consistent flowering on a trim, compact form.
How to propagate
New Guinea impatiens is most easily multiplied from cuttings, a simple way to carry a favorite planting into another corner, while a few seed strains suit those who prefer to start from scratch.
Stem cuttingsEasy
Spring to summer during active growth · 2 to 4 weeks to root
Most New Guinea impatiens begin as tip cuttings taken in spring or summer while the plant is in growth, and they settle in and root over about 2 to 4 weeks, an easy way to fill a second pot for another corner. Do note that many named cultivars are patented, so propagating them at home may not be legal.
SeedModerate
Indoors 8 to 10 weeks before last frost · 10 to 14 days to germinate
Only a few seed strains, such as the Divine series, lend themselves to this. Sow indoors 8 to 10 weeks before the last frost, rest the seed on the surface since it needs light, and keep it warm around 70°F to 75°F (21°C to 24°C) until it appears in 10 to 14 days.
Myths
New Guinea impatiens suits full sun in any setting, much like the usual sun-loving annuals.
They welcome more light than common impatiens, which opens up sunnier spots on a patio, yet they still want steady moisture and shade through a hot afternoon. The interspecific SunPatiens types are the ones bred for real sun and heat tolerance.
New Guinea impatiens go down to downy mildew, the same blight that erased garden impatiens.
Impatiens hawkeri and the SunPatiens hybrids stay untouched by the impatiens downy mildew that once emptied the beds of old bedding impatiens. They are the recommended stand-in for the susceptible Impatiens walleriana.