Here in St. Louis zone 5/6 mine stopped blooming around the 4th of July. This
is my second year for them and they came back very nicely, robust with plenty
of spread with no pests. I keep them contained somewhat around my gaslight. As
I only plant drought resistant plants, God provided the only water. The leaves
and stems are now green and red. To the same area this Spring I added Limerick
coreopsis and planted morning glory seeds which both are filling in nicely.
Next year your primrose should fill in nicely, as did mine.

Maggie from steamy St. Lou