When should you prune apple trees?

[zoobinshid]

Hello my dear teachers,
Would you please tell if this sentence is right or not?I want to know if we need ( the ) before apple trees or not?And what`s the difference if we add ( the ) to the sentence?

When should you prune apple trees?

Thanks in advance,

[Tdol]

If you're talking in general, then it's correct. If you are talking about specific trees, the ones in your orchard, say, then you could use the article.