Actually, only about half of bromeliads are epiphytic. I am unaware of any scientific study showing an epiphytic bromeliad becoming a terrestrial bromeliad simply because it is grown in a pot. These plants have developed over hundreds of thousands of years and I would think that it would be difficult to have them change their genetic tendencies simply by potting them up. This may be so, and I am only a hobbyist grower, but I just don't find evidence to support that notion.
"Urn Plants" are incredibly easy to grow, inside and/or outside. My plants spend their spring and summer months outside, under large oaks and then come inside for the fall and winter months. While outside, I flush all my plants' urns out with water (from a hose) every few weeks. When inside, if they are in greenhouses, I do the same hose-flushing. If in the house, I take the plants to a sink every month or so, and flush the urns out. Between flushing's, I simply keep water in the urn, adding enough so that some runs into the potting soil so that it will stay slightly moist. I use potting soil that is made up of sphagnum peat, coarse perlite, and cypress mulch so that the mix is open and well draining. Though I don't know whether my bromeliads benefit from fertilizations, I do fertilize my plants with 1/4 - 1/2 strength, general purpose fertilizer monthly. My plants are very healthy and apparently what I do works. Of course, as I previously stated, one would be hard-pressed to find an easier houseplant to grow.
