Help dying hair when your ends are bleached

Hi! I want to die my hair a red. The top half of my hair is my natural dirty blonde color but the bottom half is bleached blonde (due to my hair growing and not getting it redone). My question is, what do I use on/ do to the bleached ends so that I will end up with one solid color? I've been told to use toner on the bleached part first but I'm not sure if this is true, what that means or what to do. Thanks!