One of the best ways to save pansies from freeze injury is to put pine straw 2 to 4 inches thick over the bed during extreme cold. This traps heat in the soil, prevents it from freezing and greatly reduces exposure to cold, drying winds. As a rule, do this only when you expect the temperature to drop below 20 degrees for a long time and expect cold, dry winds. Always do it whenever the soil may freeze solid. We rarely get below 20 degrees but we have our share of cold, dry winds.
Carefully rake the straw off when the cold passes. Healthy plants can survive without protection for a short time even in single-digit cold.
Fertilize pansies with a granular fertilizer or an organic equivalent such as Pansy Mate about once a month through late November or early December. When the soil temperature drops below 50 degrees, pansy roots don't take up the nitrogen commonly used in granular fertilizers. Instead, use a liquid fertilizer containing at least half its nitrogen in the nitrate form.
Apply "pansy-vinca special," a high-nitrate, pansy-formula 15-2-20 fertilizer about every 14 days through early March. Just add it to a watering can and water the bed thoroughly. Potassium nitrate or calcium nitrate can provide good results in the winter, too.
How often you fertilize pansies with a liquid fertilizer depends on the plants' vigor. Consult the label for recommended rates.
When you're feeding over the top of the plants, apply enough liquid not only to wet the foliage but to saturate the root zone 4 to 6 inches deep.
By late February or early March, soil temperatures should have risen enough to use granular fertilizers again. Using a 10-10-10, 20-20-20, a slow-release granular fertilizer, or Pansy Mate, as you would for summer annuals, should work well for pansies for the rest of the spring.
Check the pH, too. Take a soil sample to test the soil. The pH is best between 5.4 and 5.8. A pH above 5.8 can lead to boron and iron deficiency and maybe to black root rot, a common pansy disease.
If the pH gets above 5.8, drench the bed with either iron sulfate or aluminum sulfate. When you do this, lightly rinse the pansies afterward to prevent any foliage injury. Do this every 10 days until the pH drops and stays between 5.4 and 5.8.
Too much soil moisture reduces oxygen and root growth in pansies. Try to keep the soil slightly on the dry side to harden growth before the very cold weather.
Keep the bed clean and free of decomposing flowers and leaves.
Make frequent deadheading (removing spend blossoms) and cleaning a priority. This prevents insect and disease problems. Biweekly deadheading is essential for a professional color display.
Trim lanky pansy stems from time to time to encourage branching, compact growth and improved flowering.
If you do these things consistently, your pansy beds will rival those you see at entrances of corporate buildings and botanical gardens.
Reach Sid Mullis, the director of the University of Georgia Extension Service Office in Richmond County, at (706) 821-2349 or firstname.lastname@example.org.