“长成”的英语可以翻译为：grow into;develop into;blossom into...

在有些地方，树木长成后就会被砍掉。When the trees matured they were cut in certain areas.这些男孩子长成了男子汉。The boys grew into men.这些植物五年后就该长成了.These plants ought to reach maturity after five years....