The 28-year-old star covets the British actress' ''beautiful'' blonde waves and insists it looks effortless.
She told people.com: ''I've always loved her hair. It's so beautiful and easy. It looks like she rolled out of bed -- and she probably did!''
Lauren insists her hair won't grow as long as she wants it to go, even though she's tried a number of different techniques to try to get it to lengthen.
She added: ''My biggest hair mistake it was chopping it off! It's so funny.
''My hair won't grow -- my hair has not gone past this length since I cut it seven years ago to my shoulders. I've tried vitamins, I've tried everything. It just won't!''
The screen beauty - who was catapulted to the spotlight on reality show 'The Hills' - prefers a natural look and enjoys getting ready for her day.
She added: ''Day to day I don't wear a lot of makeup and my hair is kind of, you know, just waves, I definitely love getting dressed up ... but I think lower maintenance is easier. [The key is to] have fun with it, really. It shouldn't be a task ... I know that sounds silly, but you should enjoy getting ready for your day.''
'Wilson', starring both Dern and Harrelson, is released in U.S. cinemas on March 24th.
At just 13, Robert Irwin is continuing his father’s legacy and he’s just as enthusiastic about animals as his dad.
Madonna adopted twins Esther and Stella from Malawi earlier this month.