Blooming often lasts throughout summer and in some areas, they will continue to delight the fall season with their outstanding colors. Most primrose flowers seen in gardens are Polyanthus hybrids, which range in color from white, cream and yellow to orange, red and pink.
What to do when Polyanthus finished flowering?
When they have finished just take the flowering stems off at the base. The plants will continue to grow for a while, and at this stage you can increase them by dividing the larger plants and planting out. They will then die down and disappear until next spring.
How many years do Polyanthus last?
Although Polyanthus are perennials and so potentially can live for many years, in reality most gardeners will persuade them into flower for only 3/4/5 years after which they may look a tad tired and have few flowers.