How to Plant, Grow, and Care for New Guinea Impatiens

Growing New Guinea impatiens can be one of the easiest ways to add some colorful blooms to your garden. Related to the common impatiens, New Guinea impatiens are a popular choice for any gardener looking for impatiens with a higher morning sun tolerance.

The New Guinea can be placed almost anywhere, whether on the porch with your other potted plants, in shady spots in the yard, or amongst your dark green foliage. With its colorful blooms, this flower is the perfect addition to your garden plans. They also make excellent indoor plants.

Not only are there a variety of colors these flowers come in, but their foliage varies as well. Most commonly, the leaves of this plant will be dark green, but sometimes you will see new guinea impatiens with reddish or even variegated foliage. If properly cared for, the flowers will bloom early and stay all season long. 

The perfect combination for New Guinea impatiens is partial shade and well-draining soil, but they will grow in full sun. They want consistently moist soil, which will vary depending on where you plant them and how much light they get. This plant is perfect for bringing all the beneficial insects and bees to the yard, and hummingbirds love their bright flowers. 

Because these plants have some wiggle room, let’s cover the basics so you can know what you need to do to grow New Guinea impatiens all summer. 

Overview

Plant Type Flowering annual Family Balsaminaceae Genus Impatiens hawkeri Species Impatiens hawkeri	Native Area Bismarck Archipelago, New Guinea, Solomon Isands Exposure Full sun to full shade Height 12-24” Watering Requirements Regular	Pests & Diseases Downy mildew, aphids, thrips, spider mites, root rot Maintenance Low Soil Type Well-draining, loamy Hardiness Zone 10-12

What is New Guinea Impatiens?

New Guinea impatiens are often more tolerant of bright sunlight and have more resistance to powdery mildew and fungal infections than the common impatiens. The New Guinea, or Impatiens hawkeri, are considered cousins to impatiens and make great companion plants.

Native Area

The original Impatiens hawkeri was found in a small area above Australia known as Papuasia which includes Bismarck Archipelago, Solomon Islands and Papua New Guinea from which it gets its common name. The original Impatiens hawkeri has undergone a series of hybridizations to what we have today which is more drought-tolerant and disease-resistant than its original version.

Characteristics

New Guinea impatiens are hardy annuals. In very good conditions they can also be perennials. If taken care of and cut back, they will bloom again next year. They are also an excellent plant for those who don’t want to wait until June for flowers. New Guinea impatiens often bloom in late spring and last through the summer. 

These beautiful flowers comprise four to five heart-shaped petals that could be pink, blue, purple, red, white, yellow, orange, burgundy, and even brown, depending on the variety. These flowers produce small seed capsules and are a great addition to any pollinator garden. They also pair well with some edible plants such as sweet potato vines.

Varieties

The list of different cultivars is vast and continually growing. We have selected a few to highlight here, but there are many more colors and varieties to choose from. Look out for series like Spectra, Super Sonic, Harmony Colorfall, Premium Petticoat, Celebration, Celebrette, Clockwork, ColorPower, Florific, ImPower, Magnum, MegaGuinea, Odyssey, Painted Paradise, Rollercoaster, Sol Luna, Sweetie Pie to name a few.

How to Grow

New Guinea impatiens are popular for a reason. They aren’t too tricky to take care of. Follow these guidelines to give yourself the best shot at a beautiful and colorful garden. If you have a more sunny garden go for a series like SunPatiens which will grow in full sun.

Light

The New Guinea impatiens cannot thrive in full sunny locations. They can take up to two to four hours of morning direct sunlight at most, but perform well in partial shade and will do okay in full shade too.

When you grow New Guinea impatiens indoors, be sure that they receive bright, indirect light. Afternoon shade is crucial here too, especially if you’re placing them in a sunny window. Providing afternoon shade ensures that the colorful foliage will not get scorched by hot, direct sunlight.

Water

While some series of New Guinea impatiens are more drought-tolerant than others, they all prefer to have regular water. They will soon let you know that they need more water by wilting. The best way to gauge if they have enough water is to check if the top inch of soil is dry. If so, it’s time to water.

Typically, if you are growing Guinea impatiens in pots or containers, you will need to water them more often. Be sure the soil isn’t already damp, and the planters, containers, and hanging baskets have drainage holes. Overwatering could contribute to fungal root rot, but as long as you have well-drained soil, this is less likely to occur.

When watering plants, make sure to water them at the base, not the top. Keeping the dark green foliage and flowers dry is essential to prevent diseases. We recommend using soaker hoses or a drip system in your flowerbeds. Water in the morning or early afternoon because night temperatures often drop and could damage your plants.

Soil

New Guinea impatiens need good loamy soil that is well-draining. To help retain some moisture and add additional nutrients, we recommend adding organic material to your soil. Adding compost can significantly help impatiens when growing in sandier soils, particularly for outdoor plants. Aim to have a soil pH of 6-6.5.

In containers and in the garden, add a mulch to aid in water retention and temperature regulation. Straw mulch is an excellent option for these flowering plants.

Temperature

New Guinea impatiens flowers are tropical plants that do best in USDA growing zones 10-12. Once soil temperatures reach 60°F (16°C) and daytime temperatures are favorable, New Guinea impatiens can be planted as outdoor plants after the last frost. 

Fertilizing

New Guineas are heavy feeders, meaning compost alone is not enough. To maintain its beautiful flowers all season long, you will need some fertilizer. Mix in a slow-release fertilizer when planting. Feed monthly with a balanced fertilizer during the growing and flowering season.

For impatiens in a container, use a complete water-soluble fertilizer every two to three weeks during the growing season. There is no need to fertilize during dormancy in late fall and winter.

Maintenance

At mid-season (July to August), flowers and foliage begin to become leggy. Prune back to four to six inches to improve the appearance of your plant, and promote new growth. When pruning, focus on the center leaves. This will create side shoots and result in a fuller-looking plant.

Deadheading, or pinching off flower stems after they have bloomed, will encourage new growth and more flowers.

Propagation

The easiest way to propagate New Guinea impatiens is from cuttings. Some varieties can be grown from seed, but for the most part, the seeds are sterile, or they will grow more similar to their parent plant than the hybrid one you have purchased. 

Propagating impatiens from cuttings can be done in either water or soil. Just cut a non-flowering stem, make sure the impatiens cutting has at least two nodes on it, and cut just below the node. Pinch off any lower leaves as well. 

If you decide to put your cuttings in the soil, you can put them in pots, trays, or directly in the ground. Just make sure the soil is moist when you put it in and that you continue to water it generously and place it in bright, indirect light. Use rooting hormone powder to speed up rooting which can take up to a month. 

For water propagating, place the cutting in a glass of water that is filled up enough to cover the first couple of nodes. Replace the water every other day to keep it fresh. Once the cutting has rooted, you can plant it in its more permanent location. 

Care for your cuttings as you would any other cuttings until they’ve developed a healthy root system by ensuring they have enough moisture, humidity, and other necessary survival needs.

Common Problems

There are a few problems to be wary of with New Guinea impatiens. Most of these issues can be avoided if you make sure to give your plants the right amount of water. Also make sure to position them in the garden properly to give just the right amount of light and only plant out after any chance of frost has passed.

Pests

Aphids, thrips, and spider mites all love to suck the life out of a new guinea impatiens plant, and you should be on the lookout for them. Yellowing, stippled leaves, sticky spots that look like black mold, or fine web-like material are signs that you may have a pest on your hands. See if you can find any on the stems of your leaves. That is where they are sucking out all the nutrients and killing your plants. Blast your plants with a stream of water. Neem oil to help prevent and suffocate these pests and try insecticidal soap. For severe outbreaks, consider a pyrethrin spray.

Diseases

One of the biggest issues to watch out for is root rot. New Guinea impatiens need a lot of water, but extended periods in poorly draining soil can create conditions that promote harmful fungal development. If the stems or roots are black, they most likely have root or stem rot. Prevention is your best bet.

If symptoms of root rotting such as yellowing or wilting develop, carefully unpot or dig up your impatiens and examine the root system. Prune off severely-damaged roots, leaving enough to sustain the plant, then replant it.

Because impatiens need a lot of water, they become susceptible to downy mildew, a type of water mold. The foliage will begin to turn yellow and curl down. If you look on the underside of yellowed leaves, you will see white fuzzy growths. The best thing to do to eliminate the spread is remove the infected foliage and reexamine your watering methods. 

Once you have removed the damaged foliage, apply neem oil to the rest of your plant. Another option is using a copper fungicide. This can help prevent and protect plants from becoming infected, and like neem oil, it should be used before any outbreak has occurred, and definitely if one appears. 

Frequently Asked Questions