As a high schooler, and through college, I ran a small backyard greenhouse selling tropical plants from my parents home. One of the groups that I specialized in were bromeliads, so I’ve long had a fascination with group. Later in life, when I switched to outdoor winter hardy plants, I continued to look for hardy bromeliads that can tolerate our winters, which drop into the single digits F every few years. We have only found three so far, which are long term survivors, Dyckia choristemae, Puya dyckoides, and of course Tillandsia usneoides (Spanish moss).
It appears, we may be able to add Puya coerulea to the list. We planted a couple of these in the crevice garden in 2019, and here they are in December 2023. We haven’t had any flowers yet, but are hopeful for next spring. Most of the information we’ve read about the species gives it a winter hardiness of 18F, but our plants made it through last years 11F, with some minor foliage burn, so we’re hopeful. The key with the hardiness of terrestrial bromeliads is to keep them very dry in winter, which the crevice garden accomplishes well.