Yup it's a June chrysanthemum! I've had these plants on one side of the house for years and they now start to flower in June.
By September they are all gone :-(
Last year I went to a garden store and they doubted I had chrysanthemums so I cut some off and went back and they were stunned. They suggested that if I didn't want flowers in June to trim them back in late May or early June so today I got out the hedge clippers and trimmed them back.
I'll let you know what happens over the next few months. I'm guessing they'll be back.