它们通常需要数百年的时间才能长成成熟的植物。

They usually need hundreds of years to grow into adult plants.

youdao

必须使用在未成熟的植物上。

Must be applied to immature plants.

youdao

成熟的植物比幼苗长得慢。

Mature plants grow more slowly than young ones.

youdao

The laurels and the myrtles that he addresses here are, of course, the traditional plants classically associated with great poets; but for Milton in this passage, importantly these plants simply aren't ripe yet.

诗中提到的月桂树和常青藤，传统上常常与伟大诗人相联系;,但在弥尔顿的这首诗，重要的是这些植物尚未成熟。

耶鲁公开课 - 弥尔顿课程节选