How To Grow And Care For Impatiens

To beginning gardeners, impatiens can be a great confidence builder. Inexpensive transplants planted after the last front in spring or early summer grow to knee-high mounds of showy flowers in a rainbow of colors by summer's end. Impatiens look beautiful in pots or in a mixed bed, add color to shady green spots, and laugh at hot, humid weather as long as they're given plenty of water—these are thirsty tropical flowers, after all. Impatiens are traditionally grown in part or full shade, but there are new hybrids that will take full sun. Every garden has a spot for these fast-growing, cheerful flowers, whether it's a container on your pool deck or growing in a sea of ferns under a shade tree. But there are a few things you should know about caring for impatiens that we'll share below.

Plant Attributes

Impatiens Care

In their native environment, impatiens grow as subshrubs in wet, tropical forests. They will thrive if you try to recreate those conditions in your garden. Give them rich, moist soil with good drainage and a spot in full or partial shade (New Guinea impatiens and SunPatiens® can tolerate afternoon sun, as long as they are well watered). Follow our tips below for growing healthy plants covered in blooms.

Light

Old-fashioned impatiens (I. walleriana) do best in full shade, dappled sunlight, or morning sun and afternoon shade. In deep shade, they can grow lanky and bloom less.

For nonstop color in a sunny or partly sunny garden, try the New Guinea hybrids that tolerate bright light. New Guinea impatiens may still need some protection from the sun during the hottest hours of the day. Without frequent watering, full-sun exposure can fry the margins of leaves and cause buds to drop.

SunPatiens hybrids are the most tolerant of full sun and hang onto their flowers and foliage on the hottest days. They also do well in part sun, but in full shade, they will flower less.

Soil

Impatiens grow best in moist, rich, slightly acidic, well-drained soil, such as high-quality potting soil. If you are planting in the ground, amend the soil to improve drainage and enrich the soil. This is especially important with heavy clay soil. A thin layer of compost will help provide plants in the landscape with a good start. You can also lightly mulch around plants to help retain moisture, but don't pile the mulch up against the stems.

Water

Traditional impatiens and New Guinea impatiens need frequent watering, especially in the heat. Check the soil for dryness daily. The plants will wilt dramatically but usually bounce back quickly once watered. Potted impatiens may require watering twice on hotter days. If impatiens are beginning to wilt or the top inch of soil is dry, water the plant right away. They drink a lot of water. Otherwise, water in the morning so that any leaves that get wet have time to dry before the sun goes down. Watering at the plant’s base is best for keeping the foliage dry.

Though far from drought-tolerant, SunPatiens are more tolerant of dryness once they are established. They still need a good soak in hot weather. Don't overwater any impatiens, however, which can cause the plants to rot.

Temperature And Humidity

Impatiens are quite tolerant of humidity and high temperatures but do not like to dry out. Expect to water more frequently when temperatures climb into the 90s or when the weather is hot and dry.

Impatiens don't tolerate cold weather and will wilt and die once frost arrives. Don't plant impatiens outdoors until after the last frost of spring; it's best to wait until nighttime temperatures remain at 50ºF or higher.

Fertilizer

Impatiens benefit from a moderate amount of fertilizer. For potted plants, use a water-soluble fertilizer every two to three weeks. SunPatiens recommend diluting the fertilizer to 1/3 strength to avoid over-fertilizing, which can result in fewer flowers and leaf burn.

For landscape beds, use slow-release fertilizer granules and apply at the recommended rate. Follow the directions on the label on when to reapply.

Types Of Impatiens

Gardeners have grown endless varieties of impatiens over the years, but the plague of downy mildew has shifted the focus to breeding and selling impatiens that are resistant to disease. Fortunately, successful breeding programs mean you can find a wide variety of impatiens today for shady or sunny gardens. Beyond the traditional red, white, and pink flowers, growers offer impatiens with bold tropical colors, frilly rose-like flowers, or striking variegated foliage:

• SunPatiens: A cross between New Guinea impatiens and unspecified species that is tolerant of full sun as well as partial shade, this variety is resistant to downy mildew. Flowers come in whites, reds, pinks, purples, and oranges. The 'Tropical' series has dark green leaves with a variegated yellow center.
• Beacon® Impatiens: Introduced in 2020, these I. walleriana cultivars were bred to be highly resistant to the downy mildew that plagued the species. Flowers come in white, red, salmon, coral, rose, violet, and orange. They perform best in two to four hours of direct sunlight a day.
• Imara® XDR Impatiens: Here's another I. walleriana series bred for superior disease resistance, but this one does best in the shade. Flowers are available in purple, red, rose, salmon, white, and the white-striped Orange Star.
• Infinity® Impatiens: This New Guinea impatiens comes in reds, pinks, purples, orange, salmon, and white and has deep green leaves. Like other I. hawkeri, the plants are more tolerant of full sun, but require a lot of water. The leathery leaves of New Guinea impatiens are naturally less prone to downy mildew.
• Bounce™ Impatiens: This New Guinea hybrid is disease-resistant and named for its ability to bounce back after missing a watering. It's available in white, pink, orange, red, violet, and purple.
• Florific® Impatiens: Another New Guinea hybrid, this type is bred for showy flowers and dense growth. It is available in red, white, purples, and Sweet Orange, a bi-colored light salmon with a deep orange center.
  
• Glimmer™ Double Impatiens: This new series of double impatiens (I. walleriana with showy flowers that look like miniature roses) was bred to be resistant to downy mildew. Flowers come in white, deep reds, pinks, and salmon.
  

Pruning Impatiens

Impatiens can become leggy in late summer, especially in deep shade. To promote bushier growth and more flowers, trim off the top 1/3 of the plant. This approach can also be used with impatiens that begin to shade out their neighbors—'Vigorous' SunPatiens can sometimes reach as much as 3 feet tall.

Propagating Impatiens

Trademarked plants cannot be propagated legally, but old-fashioned varieties without a registered trademark are easy to grow from cuttings. Using sterile pruners, cut three-inch sections of stem. Remove all but the top set of leaves and stick each stem in moist potting soil. Place in a shady spot and keep the soil moist. Transplant once a good root system has developed.

How To Grow Impatiens From Seed

You can purchase many kinds and colors of impatiens from seed companies (SunPatiens is an exception). In most climates, seeds should be started indoors eight to 10 weeks before the last frost date. Fill a tray with seed-starting mixture and moisten. Sprinkle the seeds over top, lightly pressing to make contact with the soil (the seeds must be exposed to light to germinate). Use a clear plastic dome or sheet of plastic over top and keep moist. The seeds germinate in about three weeks, with plants taking about three months to bloom.

Potting And Repotting Impatiens

Impatiens make excellent container plants. Placed in pots, their bright colors can add cheer and a tropical flair to an entrance, deck, or patio. If you set out white impatiens around these high-traffic areas, at night their flowers will glow like little stars. Plant impatiens in high-quality potting soil in a container with good drainage. You can place a saucer underneath to conserve moisture in dryer weather.

Small transplants can take a while to fill a pot, especially during cooler weather. By the end of summer, the mounded plants grow bushy and can reach 18-24 inches wide. You can pack three to five small plants into a large container about six inches apart, and then choose to separate them once they grow larger. You can also pot impatiens with other plants for contrasting foliage or color, but keep in mind that impatiens soak up a lot of water.

Overwintering

If you don't live in a frost-free area, impatiens can be brought inside for the winter. Impatiens that are not already growing in a container can be dug from the garden and placed in high-quality potting soil. Cut the plants back 1/3 to 1/2 when you do so.

If the plant is not already growing in a shady spot, move it to a protected area such as a porch first to acclimate the plant to dimmer light. Then place in bright light indoors (direct morning light is desirable) and water only when the top inch of soil is dry. Do not fertilize plants over the winter. Once night-time temperatures have warmed, place the pot in a shady spot outdoors for an hour and gradually increase exposure to outdoor temperatures and light.

Common Pests & Plant Diseases

Especially with the new disease-resistant varieties, impatiens can be fairly carefree plants. Here are some of the common problems and pests gardeners may face with impatiens:

• Downy mildew: This fungus causes whitish-gray patches on leaves of old-fashioned impatiens, but fortunately is less of a problem today. The fuzzy patches begin on the underside of leaves, and leaves begin to curl and die. The best recourse is to remove and destroy any infected plants.
• Powdery mildew: Tops of leaves are dusted with white or gray fungus. Remove infected leaves, improve spacing and airflow, and spray the plant with a fungicide for powdery mildew.
• Stem or root rots: Various fungi can infect stems or roots of plants. The base of stems may turn brown and leaves begin to yellow, usually in cool, wet soil with poor drainage. Plants become stunted. Remove and destroy plants.
• Bacterial leaf spot: Various bacteria cause small, reddish-brown spots on leaves. Stems may turn brown and rot. Remove infected plant parts (in some cases, pulling the whole plant may be necessary). Avoid overwatering or watering leaves. Spray with a copper fungicide.
• Aphids: Soft-bodied insects pierce leaves and leave a sticky residue behind. Remove them with a stream of water and spray plants with insecticidal soap.
• Mites: Cyclamen mites are practically microscopic, but can distort foliage by sucking juice from leaves and stems. Plants often have to be removed and destroyed. Tiny spider mites will leave small dots on foliage and can often be detected from webbing on the plant. Spray plants with a strong stream of water every day or two to control the infestation.

How To Get Impatiens To Bloom

Normally, impatiens will bloom from spring until the first frost. If you're having trouble getting impatiens to bloom, weather or light exposure are the most likely culprits. Impatiens are known as shade-lovers but don't bloom as well in deep shade. Increasing light exposure may help.

With the exception of SunPatiens, hot weather may cause blooms to drop. Provide more protection from the afternoon sun if this applies to you, and make certain to water well in hot weather. Cold night-time temperatures can also impact blooming.

Impatiens do not require deadheading, but if your plants have grown spindly, pruning away the top 1/3 of the plant may encourage more blooms.

Common Problems With Impatiens

Impatiens have a few common problems that are not caused by pests or disease. Here's what to do if you have these issues:

Yellow Leaves

Yellow leaves can be a sign of excess water, especially in poorly drained soil or after heavy rainfall. Empty any saucers under potted plants. Only water when the top inch of soil is dry.

Browning Leaves (Sunscald)

The margins of leaves can turn crisp when they dry out, especially in full sun. Provide protection from afternoon sun if needed. Water to keep moist, but not soggy.

Wilting Plant

The entire plant will wilt if in distress from lack of water, but your impatiens should recover if you catch it in time. Give your impatiens a good drink—potted plants may benefit from a saucer to provide an extra reservoir of water.