I just saw the Thousand-Flower Chrysanthemum at the US Botanic Garden. This umbrella-shaped beauty is a single plant. All the flowering branches grow off a single slender stem. Creating this example of “ozukuri” involves exploiting the physiology of chrysanthemums.
To create the plant, the gardeners first had to trick it into growing without producing flower buds. To do so, they turned on grow lights in the middle of the night, so that the plant thought it was in a season of short nights, a season when growing–not blooming–is the order of business. In addition, it got more photons (i.e., energy) during its artificial extra day. Next, gardeners pinched the stems to establish five major branches. As secondary branches developed off the structural branches, they were tied to vertical stakes.
When the plant reached the desired height, the vertical stakes were removed and the branches were retied to an aluminum frame. Meanwhile, the gardeners had pinched off all the buds except those on the branch ends. Not only did this create the dome shape, it directed the plant’s energy away from making lots of small blossoms and into making fewer, but bigger, ones. Grown at Longwood Gardens, the USBG’s mum actually “only” has some 600 blooms.