First, purchase a number of plants already blooming. I got two, in yellow plastic pots with a few questionable leaves and withered blooms, but numerous buds at the center. 99 cents each and 14 cents to the government.
Primroses can withstand cold temperatures but I bought mine on a gloomy day when the wind chill was excessive, so wrap them well at the grocery store or wherever you purchase your primroses. (All but three of my house plants died at some point in the last year, although recently I dusted them off and began watering with a special plant fertilizer.)
After you get your primroses home, assess the situation and pinch back or snip with scissors unhealthy leaves and dead blossoms. Ignore the helpful plastic tag that tells you how to care for primroses. In fact, throw it away.
Place the plants where they can be seen frequently, preferably on a windowsill. (I move mine from kitchen to parlor for a combination of sunshine and cooler temps.) Water as needed; primroses look awful when thirsty, but perk right up after tap water mixed with Blossom Booster fertilizer, the blue sugar-textured stuff that comes with a tiny scoop, costs more than ten primroses but lasts for years.
My current primroses are a gift to myself for not being in the hospital for one month as of March 20th. In the past, I'd buy 4 or 5, killing all of them, even after planting them outside. Too much water, too much shade, too hot, not the right soil or drainage, whatever. I was a primrose killer.
In the last days of March, I turned to the Internet, finding some places consider primroses dangerous because they spread easily, can overwinter, and are not a native species. But that is not here. When the nights in New Jersey no longer go below freezing, I will plant them outside, perhaps among other perennials in the neglected rust garden.
*thanks to jessicaj for the message which led to this