Some years back,
Only a couple of them managed to take root, & for the time since then, only the leaves grew. We'd given up the idea of them fruiting.
Then, late last year, November-December, a flower appeared in the center of the plant to the right of the garden path, & gradually has taken on the familiar pineapple form.
& even later in December, the plant on the lefthand side of the path, perhaps prompted by the nearby activity, launched into bloom.
Am unsure, but I think they take about six or so months to get to the point of harvesting.