I started two flats of impatiens from seed about two months ago. They are all very large plants, I've planted some in containers and some are still in the cells.

There are no blooms! They look very healthy, and I've fertilized them once or twice with a bloom booster, but still no blooms.

I did pinch some of the taller ones when I potted them in containers, so could see why maybe those are taking their time, but the ones in the original cell packs are also not blooming.

Any advice? I've never had impatiens that didn't bloom.