Move the primroses inside ahead of the first frost to keep them from going dormant. Put them in an indoor site where they get morning sun and afternoon shade, indirect sun or artificial lighting. Keep primroses out of all-day winter sun, which will burn them. Maintain temperatures of 65 to 75 degrees F to keep the primroses active and growing.
Water the primroses with 2 inches of water every four to five days, and spray them with water at this time as well. Primroses need moist air and soil, and dry more quickly in the house than they do outside. Don't put the primroses near fireplaces or heating vents, as the dry air dries and burns the plants.
Feed primroses once a month with water-soluble bloom or balanced fertilizer to keep them growing and blooming. Use the fertilizer mixture in place of a watering.