How to Grow Impatiens
Impatiens walleriana
The classic shade-garden annual — months of nonstop color where little else blooms.
By the Plants by Zone Editorial Team · Reviewed June 1, 2026
About impatiens
Impatiens are the premier annual for shade and partial shade, producing a dense mound of jewel-toned blooms from late spring until frost with almost no deadheading needed. Standard impatiens (Impatiens walleriana) thrive in deep shade but are highly susceptible to impatiens downy mildew, a devastating pathogen that has changed the market since 2011. New Guinea impatiens and interspecific SunPatiens hybrids resist the disease and tolerate more sun, making them the recommended choice for most home gardeners today.
When to plant and harvest impatiens
Timing is relative to your frost dates. Find your USDA zone for exact dates, or browse the month-by-month calendars.
Start seeds indoors
10–12 weeks before last frost; maintain 70–75°F and bright light
Transplant outdoors
After last frost, once nights stay above 50°F
Direct sow
Not practical — dust-fine seed needs warmth, sustained moisture, and light
Harvest
N/A — self-cleaning; spent flowers drop without deadheading
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How to grow impatiens step by step
- 1
Choose your type: New Guinea impatiens and SunPatiens interspecific hybrids resist downy mildew and tolerate more sun — they are the safer choice for most beds. Reserve standard I. walleriana for containers where you can monitor for early mildew symptoms.
- 2
Start from transplants (the reliable route) or surface-sow seed on moist mix at 70–75°F under very bright light 10–12 weeks before last frost — do not cover the dust-fine seed.
- 3
Set out after the last frost in part to full shade in rich, moist soil; morning sun with afternoon shade suits most types beautifully.
- 4
Water consistently and never let the soil dry out — impatiens wilt dramatically but recover if watered promptly.
- 5
Pinch young plants once above the second leaf pair to encourage a bushier habit; established plants spread readily on their own.
- 6
Feed monthly with a balanced fertilizer; excess nitrogen pushes leafy growth at the expense of bloom.
Common problems growing impatiens
⚠ Sudden wilting and collapse to bare stems (downy mildew)
Impatiens downy mildew (Plasmopara obducens) causes leaves to pale, then a white crust forms on leaf undersides, and the plant collapses. Remove and bag all affected plants; spores persist in soil for years. Replant only with resistant New Guinea or SunPatiens types.
⚠ Crown and root rot
Almost always overwatering or poorly drained soil — improve drainage and let the top inch dry slightly between waterings.
⚠ Spider mites (fine webbing, stippled, dull leaves)
Mites flare in hot, dry conditions. Mist the foliage daily, increase watering, apply insecticidal soap, and move containers to a shadier, more humid spot.
⚠ Aphids clustering on tender tips
Knock off with a firm blast of water; insecticidal soap handles persistent colonies.
✓ Good companions for impatiens
✗ Keep away from
🧺 Harvesting impatiens
Impatiens are self-cleaning — spent flowers drop on their own, so no deadheading is needed. Keep them watered and fed through the season for continuous color. If the plant gets rangy mid-season, shear it back by one-third and it rebounds within two weeks with dense fresh growth and a new round of bloom.
Impatiens: frequently asked questions
When should you plant impatiens?＋
In most regions you start seeds indoors 10–12 weeks before last frost; maintain 70–75°F and bright light, then transplant after last frost, once nights stay above 50°F. Timing is relative to your last frost, so find your USDA hardiness zone for the exact planting dates where you live.
Can I grow impatiens in full sun?＋
Standard Impatiens walleriana needs shade — full sun wilts and scorches them. New Guinea impatiens and SunPatiens hybrids are bred for partial to full sun and are the right choice for sunnier spots.
What is impatiens downy mildew and how do I avoid it?＋
Impatiens downy mildew (Plasmopara obducens) has devastated standard I. walleriana since around 2011, causing rapid collapse. The fix is simple: grow New Guinea impatiens or SunPatiens interspecific hybrids, which are not susceptible to this pathogen, and avoid planting standard I. walleriana in beds where the disease has appeared before.
Sources & review
Written and maintained by the Plants by Zone Editorial Team. Planting times are based on USDA hardiness zones and NOAA frost-date normals, with care guidance drawn from Cooperative Extension sources. Last reviewed June 1, 2026.
USDA Plant Hardiness Zone MapNOAA U.S. climate normalsCooperative Extension
Grow impatiens in your zone
See exactly when to plant and what else to grow alongside impatiens, tailored to your USDA hardiness zone.
