Sienna Miller is a Chelsea Flower Girl

Sienna Miller checks out the Chelsea Flower Show at the Royal Hospital Chelsea on Monday (May 18) in London, England.

The 27-year-old British actress will be one of the presenters for the 2009 MTV Movie Awards. Other presenters include Sandra Bullock, Dwayne Johnson, and Channing Tatum, for the show hosted by SNL‘s Andy Samberg on May 31st.

Sienna is preparing for the big August release of G.I. Joe: The Rise of Cobra where she plays the sexy Baroness.

10+ pictures inside of Sienna Miller at the Chelsea Flower Show…