Do I wait until all the flowers have bloomed and gone to seed? I did that with one plant last year and it didn't return this spring. I hate to deadhead before the show is finished but sure do want that second flush this year.
If you want more flowers, don't let it make seeds. Al
and you would remove individual flowers.. not the whole stalk at once ...
Nope, do remove the whole stalk, down to the lower leaves (usually around 1foot tall) as soon as the main spike of flower has died back - more side shoots will appear for a later show around late August (if you give them a little extra food and water)