Impatiens are colorful annuals for shade and part-shade beds, baskets and containers. University of Minnesota Extension lists heights of 6 to 30 inches depending on cultivar and notes that bedding (walleriana) types usually need shade while New Guinea impatiens tolerate more sun. Downy mildew is the main risk for walleriana.
Impatiens at a glance
| Type | Flower |
|---|---|
| Season | Warm-season |
| Sun | Shade to full sun, by cultivar |
| Plant spacing | 10 in |
| Row spacing | 10 in |
| Per square foot | 1 |
| Seed depth | At surface |
| Days to maturity | Start seed 10–12 weeks before planting out |
| How to start | Plant outdoors once soil temperatures are above 60°F. |
| Water | 1 in per week |
These are the same numbers our plant spacing, square foot and harvest date calculators use. See every crop in the plant database.
When to plant impatiens
Plant outdoors once soil temperatures are above 60°F. To start from seed, begin walleriana 10 weeks and New Guinea 12 weeks before outdoor planting; walleriana germinates in 5 to 15 days at 72 to 77°F, New Guinea in 12 to 25 days at 75 to 80°F, after which both grow at 65 to 70°F. Use the frost dates by ZIP code and planting calendar.
How to plant impatiens
- Match light to the type. Light needs depend on cultivar: full shade, partial shade or full sun.
- Space 8 to 12 inches apart; use the plant spacing calculator.
- Use fertile, well-drained soil high in organic matter, pH 6 to 6.5. Add compost to sandy soil and compost or sand to heavy soil.
Caring for impatiens
In beds, water when the top 1 to 2 inches of soil are dry. Containers need watering daily and hanging baskets at least once a day, and all need drainage holes. Dropping leaves signal too little moisture. See the garden watering calculator. Deadheading is not necessary.
Companion plants
| Grow nearby | Coleus, begonias and ferns in shade |
|---|---|
| Keep apart | Hot, dry, full-sun sites for walleriana |
New Guinea impatiens are more sun tolerant and more mildew resistant, with larger, showier foliage. Check other pairings with the companion plant finder.
Common problems
| Problem | What you see | What to do |
|---|---|---|
| Downy mildew | Walleriana is very susceptible | Once infected, there is no cure. Remove a few infected plants rather than treating all of them, and if it becomes a major problem consider skipping walleriana for a year or two. A general-purpose fungicide can be sprayed several times a season to control spread. Resistant cultivars are being developed. |
| Wilting or leaf drop | Leaves dropping | Too little moisture. Water when the top 1 to 2 inches are dry. See the overwatering checker. |
Not sure what you are looking at? The plant problem identifier ranks likely causes from the symptoms you see.
When and how to harvest
Impatiens are grown for their flowers in white, red, pink, violet, coral, purple and yellow. They need no deadheading.
Plan your impatiens
- Plant spacing calculator: how many plants fit your bed
- Planting calendar: sowing and transplant dates for your frost dates
- Frost dates by ZIP code: your last spring and first fall frost
- Harvest date calculator: when your crop will be ready
Frequently asked questions
How far apart should I plant impatiens?
Space impatiens 10 inches apart in rows 10 inches apart. In a square foot garden, plant 1 per square foot.
How deep do I plant impatiens seeds?
Space impatiens 8 to 12 inches apart and plant out when the soil is above 60°F.
How long do impatiens take to grow?
Start walleriana seed 10 weeks and New Guinea seed 12 weeks before outdoor planting.
How much water do impatiens need?
About 1 inch of water a week, from rain and watering combined. In beds water when the top 1 to 2 inches are dry; water containers daily.
Why are my impatiens losing leaves?
Dropping leaves signal too little moisture; also check for downy mildew on walleriana.
Is there a cure for impatiens downy mildew?
No cure once infected; remove infected plants and consider New Guinea impatiens.
Do impatiens need shade?
Walleriana usually does; New Guinea tolerates more sun.