This is a post by staff writer Yazmin Cruz.

Save green and be green this Halloween by swapping costumes on National Costume Swap Day! Mark your calendar — it’s this Saturday, Oct. 13.

According to Green Halloween, a group dedicated to making holidays eco-friendly, if half the kids in the U.S. who celebrate Halloween swapped costumes, rather than buying new ones, the nation’s annual landfill waste would be reduced by 6,250 tons. That’s about the weight of 2,500 mid-size cars. Here’s how to get involved.

Gather up your gently used costumes and find a National Costume Swap Day 2012 event nearby. There are more than 100 events happening nationwide. Visit the official website to find swaps in Canada, too.

Can’t find a swap near you? Start your own. You’re bound to have ghoulish fun by inviting family, friends, and neighbors to exchange costumes just in time for Halloween.

Trading costumes is not the only way to be eco-friendly and save money on Halloween. You can also look for cheap costumes at thrift shops and yard sales. There’s also enough time to get crafty. Upcycled Halloween costumes can help bring new life to items that would otherwise end up in the trash.

How are you saving money on costumes this year? Don’t forget to share with us what you’re dressing up as this Halloween!

Julia is still trying to figure out what Baby Bargain Babe will be for her first Halloween. Leave your suggestions in her Halloween costume contest post!