How to Plant and Grow New Guinea Impatiens

New Guinea impatiens are a tropical plant hailing from, you guessed it, New Guinea, arriving in the U.S. in 1970. These annuals feature succulent stems and attractive foliage that create the perfect backdrop for large, colorful blooms. There are many foliage variations of New Guineas, ranging from variegated to green with bronze or purple accents.

The flowers of New Guinea impatiens (Impatiens hawkeri) are like an exaggerated version of standard impatiens flowers. The showy blossoms are composed of five slightly overlapping petals, arranged around a small, button-like center. They come in a variety of bold hues from pink and white to lavender and orange. Impatiens also have a flower spur full of nectar, which makes them a favorite amongst pollinators like moths and butterflies.

Where to Plant New Guinea Impatiens

New Guinea impatiens thrive in part shade with consistently moist, well-drained soil. However, they can also withstand full sun or shade, though the plants may yield fewer flowers in these spots. Consider adding organic material, such as compost or manure, to the soil to optimize growing conditions. A slightly acidic pH is ideal. If daytime temperatures are high, seek a spot with protection from the wind, since excessive air flow can dry out the water-loving plants.

New Guinea impatiens work well in containers or hanging baskets. They can also be grouped in flowerbeds or planted as borders near pools, walkways, or patios. Since they aren't spreaders, they won't take up a lot of space in a garden bed and mix well with other shade plants. Consider pairing them with plants that don't bloom as much—the impatiens will more than compensate for any shortage of color.

How and When to Plant New Guinea Impatiens

Late spring is the best time for planting New Guinea impatiens outside. Find out when your last spring frost is expected and plan to do your planting two weeks later.

When placing these annuals in flowerbeds, separate them by the same distance as the expected diameter of the mature plants. (Vigorous varieties may require a little extra room.) Dig a hole about double the size of the root ball. Amend the soil with compost and add a slow-release fertilizer at the time of planting.

Avoid planting your New Guineas during the hottest hours of the day, and make sure to give them a thorough soaking immediately after placing them in the ground. Add a layer of mulch around the plants to reduce water loss during peak summer months.

New Guinea Impatiens Care Tips

New Guinea impatiens are sensitive to their surroundings: They're particular about nutrient levels in the soil, and they require lots of water. But the payoff is huge: With the right care, these plants will yield a gorgeous display of tropical flowers.

Light

Spots with part shade—2 to 6 hours of sunlight per day—are where New Guinea impatiens will thrive. They perform particularly well with the combination of morning sun, afternoon shade, and eastern exposure. However, these tropical beauties can also tolerate shade and full sun (especially where daytime temperatures are moderate).

Note that lots of sunshine, especially when paired with heat, will increase their water requirements, may damage the leaves, and can reduce the size and number of blossoms.

Soil and Water

Seek moist but well-drained soil for your New Guinea impatiens, and enrich the earth with organic matter like compost. A slightly acidic pH is preferable. Soil that drains quickly reduces the likelihood of root rot.

Expect your New Guinea impatiens to need lots of water. Their leaves easily lose moisture, and this tendency is exacerbated in low-humidity conditions. They are not drought-tolerant and will often wilt when it's hot outside if they don't receive plenty of water. If they start to wilt, give them a thorough watering and they should bounce back in a few hours. However, the re-hydrated plant may still show signs of stress, including a reduction in blossoms and burnt foliage, especially if wilting occurs repeatedly.

Try not to let the plants dry out between waterings. (Hint: Plant New Guinea impatiens alongside other plants with similar growing requirements.) For established plants, a weekly soaking should be sufficient; newly planted New Guinea impatiens need more water than mature plants.

Overwatering can lead to root rot, so don't let the soil become soggy. To help prevent fungal disease, aim the water at the base of the plant, avoiding the foliage and flowers, and cut back on watering when the temperatures are cooler.

Temperature and Humidity

Since New Guinea impatiens don't respond well to cool nighttime temperatures (below 45℉), it's best to plant them about 2 weeks after the last spring frost. The sweet spot for growing them is when daytime temperatures hover between 70 and 85℉ and nighttime temperatures fall between 55 and 65℉. They will stop producing new buds when nighttime temps are 70℉ and higher. New Guineas perform well in high humidity, which reduces water loss through the leaves.

Fertilizer

New Guinea impatiens don't require heavy fertilizing. When you plant them in a flowerbed, simply add a slow-release fertilizer to the soil, and you shouldn't need to fertilize again. Container garden plants will benefit from a biweekly application of water-soluble fertilizer.

Pruning

While the plant is immature, pinching the tips of branches can help direct growth into a more attractive shape. Leggy impatiens can also be trimmed back to a leaf node, though you shouldn't remove more than 6 inches at a time.

Although New Guinea impatiens naturally drop their flowers, deadheading throughout the season will encourage blooming into the fall. This clean-up will also help you avoid the growth of Botrytis fungal mold, which can form on the dead flowers. When removing spent blossoms, simply pinch the stem back, right above the first leaf pair. If your impatiens are potted, shaking the container may also encourage old blossoms to fall off.

Potting and Repotting New Guinea Impatiens

New Guinea impatiens make great container plants for patios or even indoors. As a general rule, the pot should be about 1.5 times larger than the diameter of the plant, although there are certain fast-growing varieties that may need bigger containers. Make sure the pot allows adequate drainage of the soil, and use potting soil, not garden soil.

Pests and Problems

Fortunately, New Guinea impatiens are resistant to downy mildew, which can quickly wipe out other impatiens varieties. Common garden pests, like aphids, thrips, caterpillars, and spider mites, may invade New Guineas, though they're typically pest-free.

While these tropical plants require lots of water, they're also susceptible to fungal root rot. This may occur in poorly drained soil or in containers that lack a hole for drainage.

How to Propagate New Guinea Impatiens

Most varieties are propagated by stem cuttings. Cut 2 to 3 inches from the tip of a healthy-looking stem, disinfecting your garden shears with alcohol beforehand. Remove all of the leaves except for the top two. Stick the cutting into moist potting soil, and apply heat to the bottom of the pot if possible with a waterproof heat mat designed for plants.

As hybrids, most types of New Guinea impatiens are sterile and cannot be grown from seed. A few types, such as the Java and Divine series, may be propagated this way, but often with difficulty. And if the cultivars are patented, propagating them may be illegal.

If you want to start your New Guineas from seed, plant them indoors about 10 to 12 weeks before you plan to move them outside (roughly 2 weeks after the last spring frost). Fill a starter tray with seed-starting mix, then place two seeds into each compartment. Only lightly cover the seeds with soil, since New Guineas require light to germinate. After misting the seeds, cover the tray with plastic. Place it in a bright spot, keep the soil moist, and take off the plastic once seedlings have two leaves. Let the new plants grow indoors until conditions are warm enough to move them outside.

Types of New Guinea Impatiens

'Celebration Bright Salmon'

'Celebration Bright Salmon' bears bold salmon-pink flowers over dark green foliage. It is a vigorous grower and reaches a height of 16 inches.

'Celebration Blush Pink'

'Celebration Blush Pink' flaunts large flowers in a soft shade of pink, which contrasts beautifully with the dark green foliage. Another vigorous variety, this cultivar grows to 16 inches tall.

'Applause Orange Blaze'

'Applause Orange Blaze' produces bright orange flowers with variegated foliage. It's more cold-tolerant than many other varieties, able to withstand cooler nights. Mature plants are 1 foot tall and wide.

'Celebration Raspberry Rose'

'Celebration Raspberry Rose' is noteworthy for its large raspberry-pink flowers over dark green pointy leaves. It grows 16 inches tall.

'Celebration Orange'

'Celebration Orange' stands out with its showy orange flowers over dark green foliage. It grows 16 inches tall in a mound formation.

'Celebration Lavender Glow'

'Celebration Lavender Glow' features large lavender-pink flowers over dark green foliage. It reaches 16 inches tall and is a vigorous grower.

'Infinity Lavender'

'Infinity Lavender' is a shade-loving variety with large lavender-purple flowers. It blooms all summer and fall and grows 14 inches tall and wide.

'Celebrette Deep Red'

'Celebrette Deep Red' produces rich red flowers that attract hummingbirds over dark green foliage. This compact variety tops out at 10 inches tall.

'Celebrette Purple Stripe'

'Celebrette Purple Stripe' features large purple flowers streaked with white. This petite type reaches 10 inches tall.

'Painted Paradise Pink'

'Painted Paradise Pink' produces pink blossoms over variegated foliage on a compact, 14-inch-tall plant. It's often grown for its eye-catching foliage, which adds color to a fall garden.

'Infinity Cherry Red'

'Infinity Cherry Red' shows off eye-catching bright red flowers all summer and fall. It grows 14 inches tall and 12 inches wide.

'Painted Paradise Lilac'

'Painted Paradise Lilac' bears large lilac-hued flowers over strongly variegated foliage. The mounding plant reaches 14 inches tall.

'Paradise Cherry Rose'

'Paradise Cherry Rose' shows off vibrant red-pink flowers on a 16-inch-tall plant. Blooming occurs from mid-spring to early fall.

'Painted Paradise White'

'Painted Paradise White' is a white-flowering variety with yellow-variegated foliage. It grows 14 inches tall.

'Painted Paradise Red'

'Painted Paradise Red' shows off vibrant red blossoms and variegated foliage. It grows 14 inches tall in a mounding formation.

'Paradise Mango Orange'

'Paradise Mango Orange' stuns with its bright orange flowers on a mounding, 16-inch-tall plant. Expect blooms from mid-spring to early fall.

'Paradise Rose on Violet'

'Paradise Rose on Violet' entices with its lavender-pink flowers striped with rose. It grows 16 inches tall and blooms from mid-spring to fall.

'Paradise Lavender on Fuchsia'

'Paradise Lavender on Fuchsia' offers showy lavender flowers with a fuchsia stripe on each petal. It grows 16 inches tall.

'Sonic Magic Pink'

'Sonic Magic Pink' bears big, candy-pink flowers streaked with white on a compact plant. It grows in a mounding habit and produces blossoms in spring and summer.

'Paradise Salmon Pink'

'Paradise Salmon Pink' features pink blooms flushed with orange on a mounding, 16-inch-tall plant.

New Guinea Impatiens Companion Plants

Dianthus

The quintessential cottage flower, dianthus is treasured for its grasslike, blue-green foliage and abundant starry flowers, which are often spicily fragrant. Depending on the type, the flowers appear in spring or summer and tend to be pink, red, white, rose, or lavender, though they come in almost every shade except true blue. Plants range from tiny creeping groundcovers to 30-inch-tall cut flowers, which are a favorite with florists.

Impatiens

What would we do without impatiens? They're the old reliable for shade gardens that need eye-popping color all season long. The flowers come in just about every color except true blue and are well-suited to growing in containers or in flowerbeds. If you have a bright spot indoors, you may be able to grow impatiens all year as an indoor plant.

Sweet Potato Vine

Among the most popular container-garden plants, sweet potato vine is a vigorous grower that makes a big impact. Its colorful foliage, in shades of chartreuse or purple, accents just about any other plant. Sweet potato vines do best during the warm days of summer and prefer moist, well-drained soil. They thrive in sun or shade.

Garden Plans for New Guinea Impatiens

Shady Foliage Garden Plan

This informal garden bed highlights shade plants with large, colorful leaves. Although the plan calls for a trio of impatiens, you can easily swap in New Guinea impatiens.

Fountain Garden Plan with Daylilies

Anchored by a fountain, this circular garden plan features a variety of colorful plants, including an abundance of daylilies and 30 New Guinea impatiens. It's great for a spot that enjoys afternoon shade.