I decided to check online a little bit too late for 2 plants. I cut off the long flowering part after the flowers bloomed and died cause I saw seed pockets in each slot. They hadn't turned brown and I didn't wait the 4 to 6 weeks. What do I do now with that long stem?
Certified GKH Gardening Expert
Just allow the stem to stay in the garden until fall when the greens die down naturally.
Here is a couple of links to help you.