I'm growing my hair so want to steer clear of chemical dyes because they kill my hair badly and restrict it to shoulder length. I'm fed up of my murky brown though.
Does anyone use henna? I'm just going to write a list of questions 
How much would I need for quite thick shoulder length hair? Lush seem to sell it in grams so I am at a loss.
If I dye it with henna and then decide in a few months I want to use chemical dye will my hair go green?
On the very ends of my hair I have the remains of a slightly lighter dye I used ages ago...will these bits go funny with the henna? Or just lighter?
How does it fade? Are roots really obvious?