What the Fluff? A Tribute to Union Square Innovation presented by Boynton Yards returns for the 19th year next Saturday, September 21 from 2:00 to 6:00 p.m. (rain date 9/22). This zany, madcap festival honors the invention of Marshmallow Fluff by Archibald Query in Somerville in 1917 and salutes the spirit of innovation that thrives throughout the city today.

This year’s theme – Somerville Over the Rainbow: No Place Like Fluff – showcases delightful and delectable tastes, sweet sights and sounds, incredible innovations by independently-owned shops, and community, sweet, community.

So, leave your sepia-toned world behind. Don your most hue-riffic ensemble (ruby slippers and rainbow attire optional), round up your sidekicks (Toto, too!), and follow the marshmallow road to the most magical square in Somerville. Just like Union Square, there’s something for everyone with a wide variety of themed happenings that promise cost-free fun for all ages:

Take part in hilarious antics with sticky activities like Fluff Musical Chairs, Fluff Limbo, a Fluff Hairdo Contest, and Fluff Jousting (yes, jousting!) on the Shenanigans Stage and hosted by Fluff Fest’s longtime Archibald Query impersonator.

Groove with Emcee Majic Alphonse from the Dojo @ Somernova on the Fluff ‘N Jam Stage, with electric performances from:

• Julie Rhodes & The Electric Co. at 2:00 p.m.
• The Velvet Dirtmunchers at 3:00 p.m.
• Flutterby “Fluff” Faeries at 3:45 p.m.
• Tenille Ja’Nae at 4:00 p.m.
• Somerville High School’s Step Team at 4:45 p.m.
• FM Collective at 5:15 p.m.
• DJ Mega Majic & DJ Dezzy spinning throughout the day

Say hello to Mayor Ballantyne who will welcome festival-goers from the Fluff ‘N Jam Stage at 2:45 p.m. and honor this year’s Mayor Joe Flufftastic Innovation for Impact Award honoree at 5:45.p.m.

Get inspired at Somernova’s Innovation Alley featuring youth inventors, a bot that makes S’MOREs, and a chance to relax in the Inno Alley Lounge and more.

Challenge yourself or friends to navigate a flufftastic parkour course hosted by Somerville pros Parkour Generations Boston.

Try your hand at old-school, boardwalk-style games including Fluff Bowling, Fluff Ring Toss, and more at the Midway Games Area (free to play, free to win prizes).

Strike a pose with colorful cutouts of your favorite Fluff characters by local artists Nathaniel Devarie and CultureHouse.

Snag your Fluff shirts, sweatshirts, trucker hats, koozies, stickers, tote bags, and more at the Fluff Stuff merch booth.

Browse more than 70 vendors who are whipping up sweet and savory Fluff-inspired dishes, crafting oodles of Fluff-themed items, and connecting festival-goers with the vital work of community groups who serve Somerville’s diverse and inclusive community.

Shop scores of local businesses who will open their doors to Fluff lovers in the lead up and during the Festival for you to enjoy scrumptiously sticky treats, buy limited edition Fluff goodies, and take advantage of other flufftastic specials. Participating businesses and their flufftastic offerings can be found at https://www.flufffestival.com/#offerings.

“There’s No Place Like Fluff to discover unique treasures at neighborhood businesses, raise a pint of Fluff with friends old and new, and dance in the streets,” said Jessica Eshleman executive director of Union Square Main Streets, the nonprofit who produces the festival in partnership with the Somerville Arts Council. “For those just discovering Union Square, What the Fluff? offers a full spectrum of unexpected opportunities to make Marshmallow-infused memories in community while helping to keep small businesses strong.”

The endlessly entertaining What the Fluff? Festival is made possible by the generosity of its sweet sponsors: Boynton Yards, Holiday Inn Boston Bunker Hill, The Hamilton Company, Somernova, Verizon, EventThem, Kerbey Harrington Pinkard LLP, Liberty Cannabis, Rockland Trust, USQ, Blue River Terps, Cambria Boston Somerville, Cookies Somerville Weed Dispensary, CultureHouse, The Goods Cannabis, MassBike, Parkour Generations Boston, Renewal by Andersen, Stanhope Framers, Middlesex Federal, Nicewicz Family Farm, Thalia Tringo & Associates Real Estate, The Durkee-Mower Company, and Teddie Peanut Butter.

“Boynton Yards is proud of this 5th year of supporting Fluff Fest and the great work of Union Square Main Streets as we come together once again to celebrate Somerville’s thriving businesses and local roots,” added John Fenton, Development Manager of DLJ Real Estate Capital Partners, on behalf of the Boynton Yards Development team.

Festivities are expected to attract 20,000 Fluff fans and traffic will be rerouted around Union Square to accommodate festival activities. Revelers are highly encouraged to walk, bike, boogie, or take public transit. For the first time in this festival’s 19-year history, Greenline service to Union Square awaits all.

For a third year, free bike valets will be offered by MassBike. Bike valets can be found on Somerville Avenue at the eastern festival entrance near Gracie’s Ice Cream and the the western entrance near Market Basket.

What the Fluff? is produced by Union Square Main Streets and the Somerville Arts Council.

Where: Somerville Avenue from Warren Street near Gracie’s Ice Cream to School Street near Market Basket in Union Square, Somerville, MA 02143

Fluff details: www.flufffestival.com

About Union Square Main Streets

Union Square Main Streets works to strengthen the dynamic neighborhood of businesses and people in Union Square. More information is available at www.unionsquaremain.org.

About the Somerville Arts Council

The mission of the Somerville Arts Council is to cultivate and celebrate the creative expressions of the Somerville community. Through innovative collaborations and quality programming we work to make the arts an integral part of life reflective of our diverse city. More information is available at www.somervilleartscouncil.org.