Why aren't the collards bolting?

Please, can't the collards bolt?  I am enjoying them, but.... I'm truly tired of greens.  We've been eating them since March, enjoying the parade from spinach to mustard to kale and collards.

The kale and collards are still holding up.  (Thankfully, the purple mustard bolted -- harvested yesterday).  Uh, surely it will be soon that the collards and kale will bolt?

I have lovely basil, parsley, thyme and chives growing vigorously, as are the climbing squash, pole and yard-long beans. The tomatoes and peppers are doing well, too.

I still have a full bed of beets with greens in the lower bed, below the house, not to mention Swiss chard in my upper beds, but both of them are easier to use than kale or collards, easily cooked and tender, like spinach.

So, please, in late June, isn't it time for the collards and kale to flower?

today's view of my raised bed vegetables
this evening's collard harvest (where are the cabbage white caterpillars?)  the butterflies are flying