Impatiens are sensitive tropical plants that tolerate only mild cool temperatures and are very vulnerable to frost and freezing conditions.

Temperature Tolerance of Impatiens

• Ideal growing temperatures: Daytime temperatures between 60°F and 75°F (15°C to 24°C) support healthy growth and vibrant blooms, with nighttime tolerance down to about 55°F to 60°F (13°C to 15°C)

• Cold sensitivity: Impatiens generally do not survive temperatures at or below freezing (32°F / 0°C). Exposure to frost or temperatures below 32°F causes damage such as wilting, leaf drop, and often death of the plant

• Brief exposure: Some impatiens may survive a very brief exposure to near-freezing temperatures (around 30°F) but this is not reliable and usually results in partial defoliation or stress

• Minimum threshold: To avoid damage, impatiens should not be exposed to temperatures below about 50°F (10°C), as cold snaps below this can stress the plant and slow growth

Protection Measures

• Plant impatiens outdoors only after the last expected frost date in spring to prevent cold damage

• If frost is forecast, bring plants indoors or cover them with frost cloths or sheets to retain warmth

• Mulching can help retain soil warmth around the roots during cooler nights

In summary, impatiens tolerate cool temperatures down to about 55°F but are killed by frost and freezing temperatures at or below 32°F. Protecting them from cold snaps and frost is essential for their survival and health.