Excuse me, when is the best time to behead?

Generally speaking, early spring germination is the best.

But willow trees are extremely resistant to pruning, even if they are cut off in summer.

Since the purpose of your truncation is to prevent lodging and eliminate hidden dangers, it is better to remove the crown as much as possible!

Even if there is only one single pile left, more branches can still grow. Don't worry, you won't die easily! !