Ornamental · Balsaminaceae
Impatiens
Impatiens walleriana
Set in dappled shade with steady water, impatiens turns a shaded corner into a summer of color.
Partial shade
59–75°F · 15–24°C
60–90 days
USDA 10–11
Overview
A shady side yard or a dim north border is where impatiens comes into its own, dressing the awkward corners that defeat most flowers. This tender East African perennial, grown almost everywhere as a warm season annual, carries beds, window boxes, and porch pots in bloom from late spring to the first frost. It settles into partial to full shade beneath a tree canopy or along the cool side of the house, exactly the setting a summer garden usually leaves bare.
The old name Busy Lizzie suits a plant that keeps its color going with so little attention, asking only for even moisture and a rest from the harsh afternoon sun. Its low, rounded habit stays between 6 and 24 inches (15 to 61 cm) tall and about as wide, so a grouping soon reads as one soft drift of color that edges a path or fills a shaded planter with ease.
One consideration shapes how the classic seed strains fit into a planting scheme: downy mildew moved through gardens and turned the old favorites into a risk. The elegant answer is to lean on the newer resistant varieties, which is why a name like Beacon belongs on the shopping list when you plan the season's look.
Care
The short version: set impatiens in partial to full shade, keep the soil evenly moist, feed monthly, and remove spent blooms to keep the color going.
Light
Impatiens are shade plants at heart, at their best in partial to full shade where they bloom without scorching. Strong, direct sun burns the leaves and leaves the whole planting wilting, so reserve it for the dappled light beneath trees or a north-facing spot that stays cool through the day.
Water
Keep the soil consistently moist, as impatiens wilt fast the moment they dry, though they usually recover once watered in time. Direct the water to the base rather than over the top, since wet foliage opens the door to downy mildew and gray mold. In heavy, poorly drained ground, ease off, because soggy roots rot.
Soil
Give impatiens fertile, organically rich ground that holds moisture yet drains freely. A little compost worked in supplies the steady, even dampness the roots rely on to keep the display fresh.
Temperature
Impatiens favor the mild range between 59°F and 75°F (15°C to 24°C). They are tender and frost ends them, so wait for warm, settled weather before you set plants out for the season.
Humidity
Ordinary outdoor humidity suits them, so there is no figure to chase. What counts is good airflow, since crowded, stagnant plantings hold the damp that downy mildew and gray mold need to take hold.
Feeding
Feed monthly through the growing season with a balanced fertilizer, or a weaker liquid feed a little more often, keeping in mind that container plantings draw down nutrients faster. Go light on the nitrogen, which pushes the soft growth aphids favor.
Pruning
Deadhead the spent flowers to keep fresh buds arriving, and trim away any damaged or diseased growth as you notice it. That small ritual keeps a planting looking its best and the air moving.
Size & spacing
Plants reach 6 to 24 inches (15 to 61 cm) tall and spread about the same, so give each room to fill out. The gap lets air move between them, which quietly keeps disease at a distance while the planting matures.
When to plant
Impatiens have no tolerance for frost, so their season starts once the cold is well behind you. Sow indoors in late winter, move the plants out after the last frost when the soil has warmed, and enjoy their color from late spring to the first fall frost.
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 the last spring frost
- Plant: After the last spring frost once soil has warmed
- Harvest: Late spring to the first fall frost
Hardiness
USDA hardiness zones: 10–11
Temperature: down to -1°C
Troubleshooting
With impatiens the leaves tell the story first, showing disease in damp spells and pests in dry heat. Reading those early cues lets you step in before a planting loses its polish. Match what you see below, then act while it still makes a difference to the display.
Yellowed, curling foliage and a border stripped to bare stems
The culprit is impatiens downy mildew, the disease that emptied bedding impatiens from gardens across much of the country. Leaves yellow and curl down, a white fuzz gathers beneath them, and within days the display falls away to bare stems. An infected plant cannot be rescued, so lift it, bag it, and keep it out of the compost.
Fix:
- Remove and bag infected plants including fallen leaves and do not compost them
- Note that fungicides cannot cure infected plants and only protectant fungicides slow spread
- Replant with resistant types such as Beacon or Imara XDR, New Guinea impatiens or SunPatiens, or switch to begonia, coleus, or caladium
Dusty bronze cast and thin webbing in summer heat
A fine speckling and dull bronze cast across the leaves signal spider mites, which move in when the air turns hot and dry. Tap a leaf over white paper and the tiny specks give themselves away. Rinse the foliage, lift the humidity around the planting, and treat with insecticidal soap or horticultural oil on the label's schedule.
Fix:
- Rinse foliage and raise humidity
- Apply insecticidal soap or horticultural oil, repeating as directed
A gray, cobwebby mold settling on spent blooms in damp air
Botrytis blight, better known as gray mold, settles on spent flowers and soft tissue when the weather stays cool and damp. A pale gray, cobweb-like fuzz drifts from fading blooms onto leaves and stems. Remove the faded flowers and any rotted parts, open the planting for better airflow, and keep water off the foliage.
Fix:
- Remove spent flowers and affected tissue
- Improve air circulation and avoid wetting foliage
Clustered specks and a sticky sheen on new shoots
Those clusters on the tender new shoots are aphids, and the sticky sheen left behind is their honeydew. They may twist the young leaves, but they seldom leave lasting harm. A firm jet of water clears most of them, with insecticidal soap or horticultural oil in reserve for any that linger.
Fix:
- Dislodge them with a strong jet of water
- Apply insecticidal soap or horticultural oil as needed
Toxicity
For a home shared with pets or children, impatiens carries good news: it is safe. The ASPCA lists it as non-toxic to cats, dogs, and horses, and it poses no poisoning risk to the other common household animals or to people. It can go wherever pets roam and children play with an easy mind.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
A welcome choice for a home with cats, since a curious nibble on the leaves or flowers won't poison them.
Dogs None
Nothing toxic here, so it sits happily in a household with dogs. A chewed stem might bring a mild, passing stomach upset, much as any plant would.
Horses None
Listed as non-toxic to horses, so it earns a place around paddocks and grazing without concern.
Rabbits Safe
Rabbits can browse the foliage without harm, and some keepers grow impatiens as a safe nibble for them.
Livestock Safe
Grazing livestock like sheep, goats, and cattle can share the garden without any risk of poisoning.
Birds Safe
Pet and backyard birds are at ease around the plant and its flowers.
People Safe
Not poisonous to people, and the flowers occasionally appear as a garnish. Even so, it belongs on the table as decoration rather than dinner, so don't make a meal of it.
Varieties
Countless impatiens have passed through fashion over the years, but a few names deserve a place in the plan, above all those bred to shrug off downy mildew.
Super Elfin
An early, compact seed series offering a broad palette to plan a color scheme around, though like most older Impatiens walleriana it gives way readily to downy mildew.
Beacon
Bred for strong resistance to impatiens downy mildew, it brings seed impatiens back to gardens where the disease had closed the door on them.
Double-flowered (rosebud) types
For a more formal, romantic look these carry full, rose-like double blooms in place of the usual flat, five-petaled single flowers.
How to propagate
Impatiens are simple to increase, whether you start a packet of seed indoors in late winter or take quick cuttings to repeat a planting you have grown fond of.
SeedModerate
Sow indoors 8 to 10 weeks before the last spring frost · Germinates in about 1 to 3 weeks; flowers roughly 10 to 13 weeks after sowing
Begin seed indoors 8 to 10 weeks before your last spring frost to have display-ready plants when the season opens. Press the seed onto the surface and leave it uncovered, since impatiens need light to sprout, and hold the mix warm at around 75°F (24°C) and humid. Seedlings appear in 1 to 3 weeks and reach bloom roughly 10 to 13 weeks after sowing.
Stem cuttingsEasy
Spring through summer · Roots in about 1 to 2 weeks
Tip cuttings taken spring through summer root with ease, settling in within 1 to 2 weeks in a glass of water or a pot of moist mix. It is the graceful way to carry a favorite planting through winter indoors and repeat the same scheme next year. Take cuttings only from healthy stock with no trace of downy mildew.
Myths
Impatiens need full sun to bloom well.
The truth sits the other way around. Impatiens walleriana is a shade plant that flowers best in partial to full shade, while hot, direct sun scorches the leaves and leaves it wilting.
Reach for a fungicide and it will heal impatiens already struck by downy mildew.
A fungicide only guards plants that are still healthy and cannot cure one already infected, which has to be taken out. The wiser course is to replant with resistant varieties.