Winter pansies, sometimes sold as ice or icicle pansies, provide a bright display of color to the winter landscape. Capable of thriving when temperatures dip into the teens, these delightful little pansies are closer in size to violas than traditional pansies. They produce abundant blooms throughout the winter in shades of blue, yellow and white. Blooming occurs all winter in zones 6 through 11, but these hardy plants survive colder climates, returning in early spring with a profusion of blooms.
Start winter pansies from nursery-grown plugs or seedlings. Look for healthy disease free seedlings. Check for a compact plant with deep green leaves at the crown. Avoid overgrown or leggy seedlings.
Prepare soil by tilling to a depth of 12 inches. Add 3 inches of organic matter, like compost or well-rotted manure, and mix in with the existing soil.
Perform a soil test to determine the pH level of the soil. Pansies require a pH between 5.4 and 5.8. Soil with a pH above 5.8 puts your pansies at risk for boron or iron deficiencies. Amend to correct pH following the recommendations on the soil test kit.
Plant pansies when the soil temperature remains between 45 and 65 degrees Fahrenheit. If planted too early, when the soil is above 65 degrees, stems stretch and develop foliage at the ends making them more susceptible to winter damage. If soil temperatures drop below 45 degrees Fahrenheit, roots are not able to take up the necessary nutrients for growth and blooming.
Space plants 6 to 10 inches apart, depending on the preferred result. Closely spaced plants create a mass of color, but this also increases the risk of insect infestation and disease. Mulch with organic material to prevent weeds and to retain moisture.
Water thoroughly. Fertilize following a 14-day schedule until March when the soil begins to warm. A pansy fertilizer of 15-2-20 is required at this time. Resume fertilizing with a balanced formula (10-10-10) once new growth appears in spring.