Here's an intriguing idea. The following plants are not usually epiphytic (epiphytic means, they grow on trees) but we noticed how happy they were when their roots were in tiny pots and then we remembered that, apart from the Astelias, they are all closely related, not only to the pineapple (which is completely irrelevant anyway) but to the epiphytic bromeliads of tropical America. When one of our customers told us how his clump of Bilbergia had grown up the hairy trunk of his Trachycarpus Palm, we decided it was time to experiment. If you live in the right areas, try planting (tying, more like) one of these into a crook of your favourite tree: