I miss the bright purple color when they are through flowering, so for the past few summers, I've spray painted the 'balls' wih purple spray paint once the color has faded away from the blooms! They hold their shape and color for quite a while,and the paint keeps them from dropping their seeds. Doesn't seem to hurt the plant itself, as it keeps coming back every year. I'll have to take picture and post it.

All three of you are correct, but it's not worth the risk to keep them on. Yes they do supply food, but again it's not worth keeping them for the stated reasons posted by others. I left berries on my raspberries, but cut them down as ripeness slowed, and the canes became brittle. It did produce about 200, so leaving 20 or so was no big deal. I could see the primocanes were weak being unable to find light till I removed the florocanes. Fall buds are on the Everbearing primocanes already. They grew 6 feet tall trying to reach over the florocanes. Hopefully they will have some lateral growth now. Yeah this year the florocanes grew all kinds of lateral growth for the 2nd summer crop, I would not forgo that crop ever again. I got 200 berries off of 3 canes. I suspect these primocanes next year will do the same, but they are a lot taller, I'll probably get 300 off the 2nd crop next summer. Plus I have 5 canes now! I have 15 other plants too :) (put in this year).

Based in Denmark/Europe my experience is that they flowers as follows: Allium Bulgaricum starts to flowers during may and continous into june (approx. duration of flowering 3-4 weeks) Allium Caerulum flowers a little later: Ignites during June and is fading out faster than July is showing up.

If the scape is completely done flowering then clip it at the base. Deadheading makes them bloom more, not harmful. You can also deadhead individual buds from the scape as they die off to tidy up if you have time.