What Do Pansies Need to Grow?

When and Where to Plant

• Plant pansy seedlings in the fall from mid-September to October, depending on when night temperatures begin to stay between forty and sixty-five degrees. If you are starting your pansies from seed, you can sow the seeds in July or August.

  You can plant pansies in flower beds and borders, but they also do well in window boxes or other planters. Pansies grow best in well-drained soil that is rich in organic matter. Prepare your soil by adding four to six inches of organic matter, such as peat moss or compost, to the soil. If your soil is heavy and clay-like, work in some sand to improve the drainage.

  Plant your pansies in full sun for the most blooms. You can also grow them in part shade, but if they do not receive enough light the number of blooms and the bloom size will be smaller.

Maintenance

• Water your pansies deeply after planting. Once they are established, give them about one inch of water each week. The soil should stay moist, but not wet. If the soil stays soggy, the roots may rot. It is best to water early in the day rather than in the late afternoon or evening to prevent disease. To help retain moisture, apply a two-inch layer of mulch around the plant. This will also help reduce weeds and provide some protection from the cold.

  Remove spent blossoms at least twice a month. Deadheading helps prevent insect and disease problems. It will also encourage the plants to continue blooming.

  During cooler weather use a liquid feed fertilizer containing fifty percent nitrogen on your pansies. Apply this fertilizer every two weeks, unless you have a warm spell. Then stop fertilizing until the cool temperatures return. Do not use fertilizers containing ammoniacal nitrogen during the winter, because it is slow to absorb and the plants may starve. When soil temperatures begin to rise around mid-March, switch to a slow-release granular fertilizer for the rest of the season.