I don't know a lot about primrose other than what you're describing sounds like evening primrose. And yes, it is very invasive and I had to pull all mine out as it was taking over the garden. I don't know about blooms staying open or closed at night.....it's a pretty plant, but too high maintenance for this older gardener.
I don't know a lot about primrose other than what you're describing sounds like evening primrose. And yes, it is very invasive and I had to pull all mine out as it was taking over the garden. I don't know about blooms staying open or closed at night.....it's a pretty plant, but too high maintenance for this older gardener.