It is no secret that all Science subject areas are heavy with new vocabulary. Posting a word wall in your room is a reminder of the new vocabulary you are accessing. So as not to overwhelm, especially when considering Multiple Language Learners, consider:
Refreshing your wall with each learning goal
Refreshing weekly after consolidating with students
Refreshing as you change strands
Focusing on common prefixes and suffixes (latin, greek) that help students derive the meaning of new vocabulary