Primrose plants can be removed from their growing pots and divided in the late spring or summer, after blooming has ceased. You can break apart the top foliage and roots with your hands, as you would separate cauliflower florets, or you can cut them with a sterile and sharp garden knife. Planted into fresh, light potting medium and watered well, the new plantlets will grow and fill out over the remainder of the growing season. Divide the primrose plants to alleviate overcrowding or to propagate the species.
Tip the potted primrose onto its side and gently coax the root mass and plant intact, out of the container.
Hold the root-ball of the primrose upright and decide the points where you can break it for new plantlets, allowing at least four to six leaves per division.
Pull the plant apart with your hands, from the top foliage down through the roots in equal chunks. Alternatively, run a clean garden knife through the top of the root-ball to divide the plantlets. Maintain equal amounts of top foliage and root material in each division.
Place each plantlet into a nursery pot or tray opening filled with fresh, sterile potting medium. Plant at the same depth as the primrose had been growing previously and gently tamp down to ensure good soil-to-root contact. Water in deeply, until saturated.
Return the new primrose plants to their usual growing location indoors and keep the soil evenly moist to wet through the establishing phase.