If I delete a TV show from my iTunes, can I download it again later?

All my TV shows and movies are taking up too much space on my harddrive. If I delete them from my library, can I download them again later to rewatch? For example, if I delete the a season of The Walking Dead to clear up space on my harddrive, can I download it again later when I'm going through Walking Dead withdrawals? If so, how do I do that? Thanks!