How to Grow and Care for New Guinea Impatiens

New Guinea impatiens is a fast-growing, clump-shaped tropical plant in the balsam family featuring prolific, showy flowers in an array of colors. New Guinea impatiens is a low-maintenance, high-performance option that blooms from spring, usually until the first frost, preferably in acidic soil. It grows best in partial sun, although it tolerates full sun with afternoon shade. It can also grow in shadier spots, like the shade-loving common inpatients.

New Guinea impatiens is mainly grown as an annual in the U.S., although it is perennial (coming back year after year) in the warmer, moist-climate USDA zones of 10 through 12.

New Guinea Impatiens Care

Here are the main care requirements for growing a New Guinea impatiens:

• Requires full or partial sun; tolerates shade although less light reduces bloom frequency.
• Grows as a perennial, returning year after year, in USDA zones 10 through 12.
• Expects heavy feeding to produce prolific blooms.
• Thrives in acidic soil between pH 6.0 and 6.5.
• Grows in temperatures between 45 and 85 F; frost kills this plant, and sweltering heat makes it struggle.
• Keep weed-free to reduce competition from other plants for nutrients or water.
• Can be grown in containers indoors and outside; when grown indoors, it will not likely flower year-round.
  

Light

The amount of sun exposure your New Guinea impatiens needs depends on your climate's temperature and moisture. New Guinea impatiens do best with morning sun and afternoon shade in a garden with eastern exposure. If the sun is bright and extremely hot, impatiens will require more water and may not bloom as profusely.

Soil

New Guinea impatiens like a slightly acidic soil pH, in the range of 6.0 to 6.5, but are not particular. These flowers need well-draining soil that holds moisture long enough for their roots to soak it up. New Guinea impatiens are heavy feeders, so add a good amount of organic matter to the soil during planting time. Once in the ground, give your flowers a good drink of water to help them establish themselves.

Water

New Guinea impatiens thrive with regular waterings. Do not let them remain dry for an extended period, or they will stop blooming and potentially die. New Guinea impatiens are not drought tolerant, yet prolonged periods of wet soil may cause their crowns to rot. Avoid watering them from the top, and use a drip hose, if possible.

Temperature and Humidity

Do not plant New Guinea impatiens outside until all danger of frost has passed and night temperatures are above 45 F. These flowers prefer day temperatures of 70 to 85 F and night temperatures of 55 to 65 F. They thrive in the high-humidity zones of 10, 11, and 12. Outside of these zones, most gardeners grow them as annuals, purchasing them as starts and then transferring them to the garden.

Fertilizer

Since New Guinea impatiens bloom all season long, they benefit from supplemental fertilizer. Give your flowers a dose of your favorite, balanced, water-soluble food for blooming flowers every three to four weeks. For the best results, reduce the regular dose by half and feed every 1 1/2 to 2 weeks. Plants exhibit the best growth with feedings spread out with more frequency at half strength. You can also mix in some compost upon planting or early and late in the season when grown as perennials.

Types of New Guinea Impatiens

New Guinea impatiens feature dark green, burgundy, variegated pointy leaves that stay attractive throughout the season. Its orange, pink, red, white, and purple flowers are similar to but larger than those of common impatiens with five heart-shaped petals. New Guinea impatiens flowers are a perfect addition to a pollinator garden, attracting butterflies and other beneficial insects.

New Guinea impatiens is constantly being hybridized. The following New Guinea impatiens varietals are coveted by growers:

• Impatiens 'Paradise Rose Flair': This top-performing variety grows iridescent red-pink flowers all season long and is up to 16 inches tall and wide.
• Impatiens 'Sun Harmony Baby Pink': This sun-tolerant type yields 2-inch-wide soft pink flowers that bloom all summer; it matures to 20 inches tall and wide.
• Impatiens 'Sunstanding Salmon': This cultivar produces coral-colored blooms, grows in shady to full sun areas, looks great in containers, and maxes out at 36 inches tall and wide.
• Impatiens 'Sunstanding Glowing Scarlet': This variety grows bright orange flowers with heart-shaped petals all summer, reaching 36 inches tall and wide at full maturity.
• ‘Celebration Lavender Glow': Flowers have a purple hue

Pruning

New Guinea impatiens requires some mid-summer pruning to maximize the blooms and promotes a bushier, more lush appearance. However, if you are happy with flower production and it has a full appearance, refrain from pruning. Pruning should include deadheading of faded blooms.

Cut back stems that have grown leggy and produce more foliage than blooms. When your impatiens becomes spindly, cut back no more than 6 inches (starting from the center stems).

Propagating New Guinea Impatiens

New Guinea impatiens starts are readily available at most nurseries, lending you so much variety. Still, they are easily grown from cuttings should you want to save money or if you love the specific cultivar you planted.

Here's how to propagate New Guinea impatiens from cuttings:

1. Gather garden shears, alcohol wipes, a glass, a pot, and soil.
2. Disinfect your shears by swabbing the blades with an alcohol wipe.
3. Select a hearty stem and cut 4 to 6 inches below the bloom.
4. Remove the leaves from the bottom of the cutting, leaving only the top two leaves.
5. Place the bottom of the cutting in a glass of water and locate it in a sunny window until it begins to root.
6. Fill a pot with potting mix, water it, and allow it to drain.
7. Poke a hole in the soil and place your cutting into the hole, covering up all the roots and about 1 inch of the stem.
8. Place the pot in a sunny indoor location, and then harden it off by relocating it outside for several days before transplanting it into your garden.

How to Grow New Guinea Impatiens from Seed

Since New Guinea impatiens are hybrids, most varieties cannot be grown from seed, as they are either sterile or will not grow true to seed. However, a few cultivars have stabilized enough so that seeds are available. These include the Divine Series, which comes in shades of white, pink, lavender, orange, and red, and the Tango, which offers dramatic fluorescent orange flowers.

To grow impatiens from seed, ensure you're in it for the long haul. Seeds must be started indoors about three months before the average last frost date.

1. Fill a tray, or a 6-pack of cells, with a seed starting mix and water the soil.
2. Plant two seeds in each cell or broadcast seeds over the tray, covering them with a dusting of soil.
3. Mist the top, then cover your containers with plastic and locate them in a bright spot.
4. Remove the plastic when two sets of leaves have formed.
5. Allow the seedlings to grow for three months before transplanting them into the ground.
   

Potting and Repotting New Guinea Impatiens

New Guinea impatiens make great potted flowers that can liven up your home's outdoor decor. Here's how to pot them from nursery starts:

1. Select a container with good drainage.
2. Create a false bottom in the pot by adding a thin layer of pebbles before filling the pot with soil.
3. If your impatiens seem root-bound, remove them from their package and gently separate the roots at the bottom.
4. Relocate the starts to the container, placing them to your liking and covering the roots completely.
5. Water the pot and allow it to drain before placing it in a sunny location outside.

Since New Guinea impatiens grow relatively small and are mostly kept as annuals, repotting them is rarely needed.

Overwintering

Gardeners who want to extend the life of their plants or relocate them outdoors in spring can bring impatiens indoors during the winter. Here's what to do:

1. Inspect the plant to ensure it is free of pests and disease.
2. Cut the plant back by a third, water it slightly, and relocate it to a sunny area in your home. (You may need to supplement with a plant light if you don't have enough natural light indoors.)
3. In spring, cut the plant back by half, repot it in fresh soil, water it, and harden it off by bringing it outside during the day for a few days after the last frost.
4. Once temperatures are reliably warm, relocate the pot to a sunny spot outdoors.

Common Pests & Plant Diseases

Like common impatiens, New Guinea impatiens can become infested with aphids and spider mites, which damage the plant by sucking its juices. Treat an infestation by first reducing the population with a spray from the garden hose. Then, spray the plant with insecticidal soap.

Necrotic spot and tomato-spotted wilt can move into an inpatiens bed infested with thrips. There is no cure for these viruses, so prevention is crucial. Eliminating thrips will thwart the chances of disease moving in.

Downy mildew, botrytis blight, and verticillium wilt are fungal conditions that can affect impatiens with soggy soil. You can prevent this by maintaining a consistent watering schedule and increasing the space between plants when planting. Once these diseases occur, downy mildew can only be controlled by removing the diseased plant, while botrytis blight and verticillium wilt may respond to a fungicide.

How to Get New Guinea Impatiens to Bloom

New Guinea impatiens bloom best in an area that receives sun and shade in the morning. It will have trouble blooming if it does not get enough water, has too much or too little sun, or needs fertilizer to give it a flower boost. After the first blooms fade, deadhead them to promote more sets of flowers.

If your garden area receives more than eight hours of sunlight daily, provide a temporary shade structure to maximize blooms. Also, maintain a regular watering routine; improper moisture conditions can affect flowering.

Bloom Months

New Guinea impatiens bloom from spring until the coming of the frost in late fall or early winter, depending on the zone.

How Long Do New Guinea Impatiens Bloom?

Blooms typically last from spring to the first frost. Since New Guinea impatiens are only perennials in zones 10 through 12, bring the plants indoors to keep them alive in the winter by placing them in a bright window or providing supplemental grow lighting. As long as they get water, fertilizer, and ample light, they will likely rebloom once relocated outdoors when the threat of frost passes.

What Do New Guinea Impatiens Flowers Look and Smell Like?

New Guinea impatiens feature orange, pink, red, white, and purple flowers with five heart-shaped petals similar to but larger than common impatiens. They have little fragrance, although some impatiens may release a mild fragrance at night.

How to Encourage More Blooms

Pruning and deadheading will encourage more blooms.

Deadheading New Guinea Impatiens Flowers

When pruning, deadhead New Guinea impatiens flowers by pinching the stems back to its first set of leaves. Deadhead regularly throughout the flowering season to encourage more blooms.

Common Problems With New Guinea Impatiens

Like other flowers, New Guinea impatiens can get sunburned and develop marginal necrosis. Brown necrosis patches on leaves are not very serious, yet they create an unsightly display. The best way to avoid this is to ensure your planting area receives ample shade.

Red Tinge on Leaves

New Guinea impatiens like regularly moist soil but not soggy. Make sure your impatiens are not waterlogged, or they will drop their flowers and develop a red tinge to their leaves. If this happens, cut back on watering, but don't let the soil completely dry out.