Ornamental · Balsaminaceae
Impatiens
Impatiens walleriana
Hand it a shady, moist spot and impatiens will pour out color for the whole summer.
Partial shade
59–75°F · 15–24°C
60–90 days
USDA 10–11
Overview
Got a shady spot that nothing seems to like? Impatiens is the answer, since few plants throw color into shade the way it does. It's a tender perennial from East Africa, grown pretty much everywhere as a warm season annual, and it packs beds, borders, and pots with bloom from late spring right up to the first frost. While most flowers pout without sun, this one is happy in the partial to full shade under trees and along the north side of a house.
That old nickname Busy Lizzie fits, because it just keeps flowering without much fuss, asking only for moist soil and a break from the hot afternoon sun. The plants stay low and mounded, somewhere between 6 and 24 inches (15 to 61 cm) tall and about as wide, so pop a few in and they soon knit together into a sheet of color.
There's one catch worth knowing about, and it's a big one for the old seed types: a disease called downy mildew that swept through gardens and made the classics a bit of a gamble. The fix is easy enough, just grab newer resistant varieties, which is exactly why a name like Beacon is worth remembering when you're picking what to plant.
Care
The short version: pop impatiens into partial to full shade, keep the soil evenly moist, feed it monthly, and pull off the spent blooms so the flowers keep coming.
Light
Impatiens are shade plants through and through, and they're happiest in partial to full shade where they bloom without burning. Hot, direct sun? That just scorches the leaves and leaves the whole thing wilting, so give it the dappled light under trees or a north-facing spot instead.
Water
Keep the soil consistently moist, because impatiens wilt fast the second they dry out, though don't panic, they usually bounce back once you water them. Water at the base instead of over the top, since wet foliage is an open door for downy mildew and gray mold. And if your soil is heavy and drains slowly, go easy, because soggy roots rot.
Soil
Give it fertile, organically rich ground that holds moisture but still drains well. Mix in a bit of compost and you've got the roots the steady, even dampness these plants can't do without.
Temperature
Impatiens like it mild, somewhere between 59°F and 75°F (15°C to 24°C). They're tender and frost finishes them off, so hang on for warm, settled weather before you put plants outside.
Humidity
Regular outdoor humidity is plenty, so there's no number to fuss over. What really matters is airflow, because crowded, stagnant plantings trap the damp that downy mildew and gray mold need to take hold.
Feeding
Feed it monthly through the growing season with a balanced fertilizer, or a weaker liquid feed a bit more often, and remember that plants in pots get hungry faster. Go easy on the nitrogen, though, since too much pushes soft growth that aphids can't resist.
Pruning
Deadhead the spent flowers to keep fresh buds coming, and snip off any damaged or diseased growth whenever you notice it. That little bit of tidying keeps the plant blooming and the air moving.
Size & spacing
Plants get 6 to 24 inches (15 to 61 cm) tall and spread about the same, so give each one some elbow room to fill out. That gap lets air move between them, which is what keeps disease at bay.
When to plant
Impatiens really hate frost, so there's no reason to rush them outside. Start seed indoors in late winter, wait to set the plants out until the last frost is done and the soil has warmed up, and you'll get bloom from late spring all the way 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, trouble almost always shows up on the leaves first, whether it's disease in damp weather or pests when it's hot and dry. Catch it early and you can step in before a small issue swallows the whole planting. So match what you're seeing below, then act while it still does some good.
Yellowing leaves that curl, then a plant down to bare sticks
This is impatiens downy mildew, the disease that took out bedding impatiens across a lot of the country. The leaves go yellow and curl down, a white fuzz shows up on their undersides, and within a few days the whole plant drops its foliage and stands there as bare stems. There's no saving one once it's hit, so pull it, bag it, and whatever you do, don't compost it.
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
Speckled, bronzy leaves and a bit of webbing when it's hot
Fine speckling and a bronze look on the leaves usually mean spider mites, which love it when the air goes hot and dry. Not sure? Tap a leaf over white paper and watch the little specks crawl. Rinse the foliage down, bump up the humidity around the plant, and treat with insecticidal soap or horticultural oil on the schedule the label gives you.
Fix:
- Rinse foliage and raise humidity
- Apply insecticidal soap or horticultural oil, repeating as directed
Gray fuzz on old flowers when it turns damp
Botrytis blight, which people also call gray mold, likes to settle on tired flowers and soft tissue when the weather stays cool and damp. You'll spot a light gray, cobweb-like fuzz creeping off dying blooms and onto the leaves and stems. Just pick off the faded flowers and any rotted bits, open the planting up so air can get through, and keep the water off the foliage.
Fix:
- Remove spent flowers and affected tissue
- Improve air circulation and avoid wetting foliage
Little bugs and a sticky film on fresh growth
See those little clusters on the fresh shoots? That's aphids, and the sticky stuff they leave behind is honeydew. They'll twist up the young leaves a bit, but they rarely do any real damage. Knock them off with a sharp jet of water, and if they keep coming back, reach for insecticidal soap or horticultural oil.
Fix:
- Dislodge them with a strong jet of water
- Apply insecticidal soap or horticultural oil as needed
Toxicity
Good news if you've got pets or kids: impatiens is safe. The ASPCA lists it as non-toxic to cats, dogs, and horses, and it's no poisoning risk to the other common household animals or to people either. So go ahead and plant it where pets graze and children play, no worries.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
Cats are totally fine around it, and a curious nibble on the leaves or flowers won't poison them.
Dogs None
There's nothing toxic here, so dogs are good near it. If one chews a stem it might get a mild, passing tummy ache, but that's true of just about any plant.
Horses None
It's listed as non-toxic to horses, so a horse grazing nearby has nothing to worry about.
Rabbits Safe
Rabbits can munch the foliage without any harm, and some keepers even grow impatiens as a safe little snack for them.
Livestock Safe
Goats, sheep, and cattle won't get poisoned by it, so there's nothing to fence off.
Birds Safe
Pet and backyard birds are perfectly okay around the plant and its flowers.
People Safe
It's not poisonous to people, and the flowers even show up as a garnish now and then. That said, it's not a food crop, so don't go making a meal of it.
Varieties
Hundreds of impatiens have come and gone over the years, but a handful of names are worth knowing, especially the ones bred to shrug off downy mildew.
Super Elfin
It's an early, compact seed series with loads of colors to pick from, but heads up, like most older Impatiens walleriana it caves fast to downy mildew.
Beacon
Here's the good one: it's bred to resist impatiens downy mildew, so you can grow seed impatiens again even in gardens where the disease has dug in.
Double-flowered (rosebud) types
Want something fuller? These give you plump, rose-like double blooms instead of the usual flat, five-petaled single flowers.
How to propagate
Making more impatiens is genuinely easy, whether you start a packet of seed indoors in late winter or just take a few quick cuttings off a plant you already love.
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
Get seed going indoors 8 to 10 weeks before your last spring frost. Just press it onto the surface and leave it uncovered, because impatiens need light to sprout, and keep the mix warm at around 75°F (24°C) and humid. You'll see sprouts in 1 to 3 weeks, and flowers turn up roughly 10 to 13 weeks after sowing.
Stem cuttingsEasy
Spring through summer · Roots in about 1 to 2 weeks
Snip a few tip cuttings spring through summer and they root with almost no effort, taking hold in 1 to 2 weeks in a glass of water or a pot of moist mix. It's the easy way to carry a plant you love through the winter indoors. One thing though: only take cuttings from healthy plants that show no downy mildew.
Myths
Impatiens need full sun to bloom well.
It's really the opposite. Impatiens walleriana is a shade plant that blooms best in partial to full shade, and hot, direct sun just scorches the leaves and leaves it wilting.
If impatiens catch downy mildew, a fungicide will just fix them.
Nope, a fungicide only shields plants that are still healthy and can't cure one that's already infected, so that plant has to go. What actually works is replanting with resistant varieties.