I have planted primroses for a guy in his back yard. I put new dirt around them and watered well. However, not all the primroses survived the winter weather.
Moss Rose is Portulaca grandiflora (Moss-Rose Purslane, Rose Moss) But Primrose is Primula vulgaris (Common Primrose, English Primrose)
I love portulaca and have had one that I potted ten years ago continue to reappear. My cats lay in the pot at night!