Are impatiens perennial or annual?

Common impatiens (*Impatiens walleriana*) and New Guinea impatiens (*I. hawkeri*) are tender perennials that survive as perennials only in USDA zones 10–12. In zones 3–9, they are killed by frost and grown as summer or shade annuals. SunPatiens and New Guinea types can be overwin

Impatiens are another tender perennial routinely sold and grown as an annual across most of the United States. The plants are killed by frost, and in most American gardens, that means one season of color and done.

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The impatiens downy mildew problem

Before discussing the perennial/annual question, this needs to be addressed: common impatiens (Impatiens walleriana) has been devastated by impatiens downy mildew (Plasmopara obducens) across the eastern United States since approximately 2011. Per Penn State Extension, the disease causes "total plant collapse within days of symptom appearance" and the pathogen persists in the soil for years.

Many gardens that planted common impatiens before 2012 cannot successfully grow them now. Per NC State Extension, "once impatiens downy mildew is established in a planting site, it is very difficult to eradicate." If you've had collapse of impatiens beds in the past, do not replant common impatiens in those beds — switch to New Guinea impatiens, SunPatiens, or begonias, which are resistant to the pathogen.

Species and their hardiness

Common impatiens (Impatiens walleriana): Zones 10–12 as a perennial. Annual treatment in zones 3–9. Susceptible to downy mildew.

New Guinea impatiens (Impatiens hawkeri): Zones 10–12 as a perennial. Annual in zones 3–9. Resistant to downy mildew. Tolerates more sun than common impatiens.

SunPatiens (interspecific hybrid): Annual treatment in zones 3–9; overwinters in zones 10–12. Highly heat-tolerant and sun-tolerant. Resistant to downy mildew.

Busy Lizzie (Impatiens balsamina, garden balsam): True annual by genetics in all zones. Completes lifecycle in one season.

USDA zone behavior

Per Missouri Botanical Garden, I. walleriana is "a tender perennial that is typically grown as an annual." In zones 10–12, common impatiens grows year-round.

Zone 7 (Long Island, DC, Nashville): Frost typically arrives in mid-to-late October. Impatiens planted in May bloom through September and are killed by the first hard freeze.

Zone 9 (Houston, Jacksonville): Plants may survive a very mild winter with some protection. After a rare hard freeze, they are lost.

Zone 10–12 (Miami, Hawaii): Impatiens grow as true perennials, flowering nearly year-round. Common impatiens can reach 24 inches tall and shrub-like proportions in these zones.

Overwintering New Guinea impatiens and SunPatiens as cuttings

For gardeners who want to carry over a specific plant, New Guinea impatiens and SunPatiens root readily from cuttings:

1. Take 3–4 inch shoot-tip cuttings in late August or early September, before night temperatures drop below 50°F.
2. Remove the lower leaves; dip the cut end in rooting hormone.
3. Insert in a sterile, moist rooting mix.
4. Cover with a plastic bag or humidity dome. Keep at 65–70°F in bright indirect light.
5. Roots form in 2–3 weeks. Pot up and grow under lights or in a sunny window.

Per Clemson HGIC, New Guinea impatiens "can be overwintered indoors in a warm, bright location." Move plants back outside after last frost the following spring.

Care for best annual performance

Shade requirement (common impatiens): Per Clemson HGIC, I. walleriana "performs best in partial to full shade" — 2–4 hours of filtered light. Full sun causes wilting and bleaching. This is what makes common impatiens irreplaceable for deeply shaded beds.

Sun tolerance (New Guinea and SunPatiens): New Guinea impatiens tolerate 4–6 hours of direct sun. SunPatiens are specifically bred for full-sun performance.

Water: Impatiens require consistent moisture. Per Clemson HGIC, they require "regular watering" — soil kept evenly moist but not waterlogged. They wilt quickly in dry conditions.

Fertilizer: Per Missouri Botanical Garden, impatiens are "moderate feeders" that respond well to a balanced slow-release fertilizer at planting, supplemented with liquid feeding every 2–3 weeks.

Common mistakes

Frequently asked

Why did all my impatiens collapse suddenly?

Per Penn State Extension, this is the characteristic symptom of impatiens downy mildew: plants appear healthy, then collapse suddenly. The leaves turn yellow and drop, and the entire plant deflates within days. There is no cure. Remove all plant material immediately, do not compost it, and do not replant common impatiens in that location. New Guinea impatiens, SunPatiens, and begonias are the reliable alternatives.

Can I grow impatiens in full sun?

Common impatiens (I. walleriana) cannot tolerate full sun — it requires partial to full shade. New Guinea impatiens can handle 4–6 hours of sun. SunPatiens are the full-sun impatiens option. Per Clemson HGIC, site selection is "the most important factor in impatiens success."

Are there deer-resistant impatiens?

Common impatiens are highly palatable to deer. Per Rutgers NJAES, impatiens are rated "frequently severely damaged." Begonias and vinca are more deer-tolerant alternatives for shaded beds.

How do I get impatiens to rebloom?

Impatiens typically self-clean. If plants become leggy in midsummer, cut them back by one-third to one-half to stimulate new branching and flower production. Per NC State Extension, this "renovation pruning" works best in early to mid-July.

Sources

1. Missouri Botanical Garden — Impatiens walleriana
2. Penn State Extension — Impatiens Downy Mildew
3. NC State Extension — Impatiens walleriana
4. Clemson HGIC — Impatiens