How-to Guide
How to Grow Impatiens
The short answer
Plant impatiens outdoors after the danger of frost is past — and hold New Guinea impatiens back until about 2 weeks after your average last spring frost (Iowa State Extension). They are the classic shade annual: sites with 2 to 4 hours of filtered sun, or morning sun with afternoon shade, are ideal.
Keep the soil moist but well-drained, water beds about once a week in dry weather, and feed container plants every 2 weeks with a water-soluble fertilizer. If you grow classic Impatiens walleriana, pick a downy-mildew-resistant series such as Beacon, Bounce, or Imara XDR.
When to Plant
Impatiens are frost-tender tropicals. Iowa State Extension says to plant standard impatiens after frost danger has passed, and New Guinea impatiens about 2 weeks after the average last spring frost, once nights are reliably mild.
Harden off greenhouse-grown plants by gradually exposing them to outdoor conditions for several days before planting.
How Much Shade?
Standard impatiens (Impatiens walleriana) do best with 2 to 4 hours of filtered sun during the day, or morning sun and afternoon shade. They tolerate heavy shade, but expect taller plants and fewer blooms there (Iowa State Extension).
New Guinea impatiens want morning sun and afternoon shade — an eastern exposure is ideal. Too much sun reduces flowering and scorches foliage.
Soil, Water, and Feeding
Impatiens need moist, well-drained soil. In garden beds, a deep soaking once a week during dry weather is usually enough; in containers, check often and water when the soil surface is dry (Iowa State Extension).
Mix a slow-release fertilizer into beds before planting. Feed container plants roughly every 2 weeks with a water-soluble fertilizer.
→ New Guinea impatiens are touchy about both extremes: moisture stress makes them abort flower buds and brown at the leaf edges, but soggy soil hurts them too.
Bloom Care
Impatiens are among the lowest-maintenance bloomers: Iowa State's growing guide lists no deadheading requirement — the real levers on bloom are light, steady moisture, and feeding. If plants in deep shade get leggy and sparse, move them (or next year's plants) somewhere brighter.
Containers and Baskets
All types — standard, New Guinea, and interspecific hybrids — work well in containers and hanging baskets. Container plants dry out fast in summer, so they drive most impatiens failures; water whenever the surface is dry.
The Downy Mildew Problem
Impatiens downy mildew hits Impatiens walleriana hard — leaves yellow, a white coating forms underneath, and plants collapse. Iowa State Extension points to resistant varieties: the Beacon, Bounce, and Imara XDR series. New Guinea impatiens are not affected the same way. If mildew wiped out your impatiens before, switch series rather than replanting the same ones.
⚠ If impatiens collapsed in that bed in a past year, don't replant susceptible Impatiens walleriana there — choose a resistant series or a different shade annual like begonias.
Sources
Reviewed 2026-07-18. We cite university Extension, government, and established horticultural sources — and never invent pesticide rates or dangerous treatments.
- Iowa State University Extension — Growing Impatiens in the Home Garden — Plant after frost danger (New Guinea ~2 weeks after average last frost); 2-4 hours filtered sun; weekly watering in beds; fertilize containers every 2 weeks; downy mildew resistant series Beacon, Bounce, Imara XDR
- Clemson University HGIC — Impatiens — Impatiens perform best in moist, well-drained soils in partial shade