The Wilton Go Green Festival will welcome spring on Sunday, May 5, with a celebration of the Earth’s bounty and a reminder to residents that everyone plays an important role in the stewardship of the planet.

Festivities begin with the fifth annual Where the Wild Things Run 5K, sponsored by Woodcock Nature Center. Approximately 90% of the 5K is run on a mix of groomed trails, rugged trails, and narrow bridges and boardwalks. Runners, joggers and walkers of all ages are welcome (no strollers). Preceding the race, children will have a fun run that takes them through the woods and over a bridge. Registration is at 7:30 a.m. at the nature center, 56 Deer Run Road. The fun run begins at 8:30 followed by the 5K at 9.

Information: 203-762-7280.

For those who prefer wheels, Sound Cyclists will offer guided rides of varying lengths and ability levels. They range from a slow five-mile ride to a fast 45 miles over hilly terrain with five more choices in between. Advance registration is not required, but participants should dress appropriately and bring their bikes and helmets.

A silent auction offers riders — and others — a chance to take home a new bike courtesy of Outdoor Sports. Other items to bid on include a summer membership at the Wilton Y, tickets to the Westport Country Playhouse, a gift card to Bon Appetit or Cactus Rose, and a variety of specialty gift baskets.

The festival officially opens at 11 with live music, an array of creative children’s crafts using recycled materials, “green” shopping, and more than 80 exhibitors eager to share best practices on energy conservation, building, transportation, recycling and waste management, and responsible stewardship of the air, land, water, wildlife and other natural resources.

At noon in the library courtyard, the Wilton Tree Committee will recognize the 2013 Steward of the Year at its annual ceremony. First Selectman Bill Brennan will open the ceremony, which will honor Young’s Nursery for its long history of service, volunteerism and generous donations of plant material to many Wilton High School graduations, the Wilton Library and the town as a whole. Mr. Brennan will also attend the Neighbor to Neighbor Energy Challenge award ceremony — a special presentation honoring Wilton’s many achievements in improving residential energy efficiency.

The festival will sprawl between the town green and Wilton Library presenting everything from the latest electric and hybrid cars to a huge, interactive Earth Balloon sponsored by Deloitte and 13-foot tall farmer created by student artists at Wilton High School. Refreshments include Skinny Pines Pizza — featuring a special Wilton Go Green pesto pie created especially for the festival — and offerings from Green Leaf Organic Café of Wilton.

More offerings:

• Young vegetable plants courtesy of Wilton High School teacher Jim Hunter and students from the school’s organic garden;

• Tips from the Wilton High School Recycling Club;

• Cooking demonstrations with Jonathan Mathias of A Dash of Salt Catering and fellow chefs at 11:30, noon, 12:30 and 1;

• Clean energy options from Next Step Living, Rings End and BPC Builders;

• City Carting’s “shredding” truck will be in the post office parking lot between 11 and 2:30.

The festival is co-hosted by Wilton Library and Wilton Go Green, and sponsored by Energize Connecticut with funding provide by the Clean Energy Finance & Investment Authority through a Community Innovations Grant. Energize Connecticut is an initiative of the Energy Efficiency Fund, the Clean Energy Finance and Investment Authority, the State and local electric and gas utilities with funding from a charge on customer energy bills.