The Best Dates to Plant Pansies

USDA Hardiness Zones 2 through 5

• The United States Department of Agriculture hardiness zones divide geographical regions based on annual minimum winter temperatures. This often correlates to elevation and latitude and provides insight into length of growing season. USDA zones 2 through 5 includes much of Canada and the northern United States. Pansies are typically planted in early spring in places like Minneapolis, Chicago, Denver, Boston and Toronto. They relish the moist, cool soils from March and April until June when temperatures often exceed 80 degrees F. Plants may continue to grow, but flower production stops when temperatures are too hot. High elevation areas in the Rockies or in the northerly Canadian forests may have cool enough summers to sustain pansies well up until the start of winter.

USDA Hardiness Zones 6 through 8

• Across the milder winter areas of the United States, in USDA hardiness zones 6b through 8, pansies are often planted in autumn. In Dallas, Atlanta, Seattle, and Richmond, the cold but mild winter temperatures occasionally drop as low as 10 to 20 degrees, allowing pansies to survive since daytime temperatures rebound to above freezing. Pansies continue growing and flowering then through spring. Typically pansies in the American Southeast and mildest areas of the Pacific Northwest are planted in October and November and bloom through May, when heat causes them to become leggy and stop producing blooms.

USDA Hardiness Zones 9 through 11

• In the subtropical and tropical areas of USDA zones 9 through 11, pansies are a winter garden annual. In southern California and the Florida peninsula, pansies are planted from November to January. They bloom nicely until spring when temperatures reliably reach above 80 degrees or sunlight intensity heats the soil too much. Since cool winter temperatures aren't guaranteed, subtropical gardeners may avoid pansies and plant other cool-season annuals not limited as much by warmth.