"Farmers and gardeners keep plants in particular arrangements for particular purposes. Some gardens are just as decorative as a gold necklace, and some are just as useful as an iron hammer, and they get that way through the care and attention of people. And of course there's miniature trees. Those are crafted in what might be a more familiar way - their custodians encourage them to grow in specific shapes, for magical reasons or just because they're pretty that way."