Halloween  is only one week away, and celebrities are getting into the spirit with trips to the pumpkin patch and costumed outings. Alessandra Ambrosio, Jennifer Garner , and Rebecca Gayheart have picked pumpkins with their families, while Cash and Honor Warren hit the pumpkin patch slide for a good time. Click through to see all the stars gearing up for Halloween, and make sure to check out over 150 celebrities in Halloween costumes  for ideas on what to wear on Oct. 31.
Heidi Klum  and Leni picked out pumpkins in LA.
Pete Wentz  and his son Bronx went shopping for pumpkins at the market in LA.
Travis Barker and his son, London, spent time together at an LA pumpkin patch.
Selma Blair  had a smile on her face watching son Arthur scurry through the hay at a patch in LA.
Alessandra Ambrosio scoured the pumpkins at Mr. Bones Pumpkin Patch with daughter Anja in LA.
Jessica Alba  snapped pictures of her family at Mr. Bones Pumpkin Patch in LA.
Rebecca Gayheart had a smile on her face as she carried her daughter Georgia through Mr. Bones Pumpkin Patch in LA.
Ian Ziering and his wife, Erin, posed for a Fall photo with their daughter, Mia, at Mr. Bones in LA.
Christina  Aguilera and her son, Max, held hands while they scoured the pumpkins at Mr. Bones Pumpkin Patch in LA.
Halle Berry  and Nahla checked out Halloween  costumes in LA.
Eric Stonestreet got into quite the Halloween  getup to film on the set of Modern Family in LA.
In LA, Jillian Michaels and Heidi Rhoades took their kids to visit Mr. Bones Pumpkin Patch.
Kingston Rossdale was dressed up in his Halloween  costume for an outing with dad Gavin Rossdale  in LA.
Gwen Stefani  and Zuma Rossdale picked out their favorite pumpkins at Shawn's Pumpkin Patch in Culver City.
Cash Warren rode a slide at an LA patch with daughter Honor.
Hilary Duff  looked adoringly at her little one, Luca, as dad Mike Comrie gave him a kiss at Mr. Bones Pumpkin Patch in LA.
Alessandra Ambrosio showed off her legs in short cutoff shorts to accompany Anja and Noah through the pumpkin patch in LA.
January Jones  strolled with her son, Xander Jones, at Mr. Bones Pumpkin Patch.
Amy Poehler  carried her son, Archie Arnett, dressed as Batman to a costume birthday party in LA.
Mila Kunis  stopped by the store to pick up some pumpkins in West Hollywood.
Pregnant Claire Danes  and Hugh Dancy stopped for some pumpkins while in Toronto.
At Mr. Bones Pumpkin Patch in LA, Jessica Alba  pushed baby Honor through the pumpkins in her stroller.
Halle Berry  and Nahla enjoyed the games at a Simi Valley, CA, pumpkin patch.
Milla Jovovich and her husband, Paul W.S. Anderson, checked out an LA patch with daughter Ever.
Julie Bowen got a head start on Halloween  fun in a costume on the set of Modern Family in LA.
Jennifer Garner  and her daughter Seraphina got pumpkins at an LA farm.
Garcelle Beauvais picked pumpkins at a patch in LA.
At a pumpkin patch in West Hollywood, Michelle Monaghan guided her little one, Willow, through the pumpkins.
Ali Larter  and her son Theodore checked out the offerings at LA's Mr. Bones Pumpkin Patch.