How can I search (case-insensitive) in a column using LIKE wildcard?

I looked around some and didn’t find what I was after so here goes.

SELECT * FROM trees WHERE trees.`title` LIKE  '%elm%'

This works fine, but not if the tree is named Elm or ELM etc…

How do I make SQL case insensitive for this wild-card search?

I’m using MySQL 5 and Apache.