Step 2. Place 2 to 3 primrose seeds onto the surface of the soil, press them into the soil to a depth of approximately ¼ inch. Avoid covering the primrose seeds with any soil. Light is necessary for primrose seeds to germinate.deal temperature is 60 to 65 degrees F. Germination is between 10 and 30 days. Once seedlings emerge, remove the plastic wrap. As soon as they reach 1 inch in height, remove all but one seedling per pot, or cell.