Each spring, the Fredrikses plant pink impatiens in 12-inch plastic pots filled with potting soil. (At planting time, they mix 1/2 teaspoon controlled-release fertilizer into the soil.) Then they set the pots into the rings. A drip-irrigation system waters each pot 5 minutes a day throughout the blooming season. In addition, each pot is fed a dilute liquid fertilizer twice a month.