Bum-Young Sung - “Spirited Garden” (text)
Chinese Elms to prune once the spring Buds harden, and once more in early or mid-July.—to ensure an even growth of branches
The buds near the tip of the strong branch should be cut off so that enough energy can go to weak ones—leading to even branches.
Once the buds become hardened, it is better to cut them off leaving only a couple of buds behind.