Answer: Kaffir lilies make great container plants and the urn you describe should suit them well, providing it has adequate drainage so the soil doesn't become or remain soggy. Overly wet soils can cause root rot. Kaffir lilies perform best when they're allowed to remain in the same spot for several years. By not disturbing the roots you allow them to become established, which results in healthy, happy plants. You'll eventually want to dig and divide your lilies, and replace the potting soil with fresh soil. You lilies may not look quite as spectacular the following growing season, but they'll adjust and perform well for a few years before it's time to divide them again. Hope this clarifies things for you.
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