When Ashley Primis was preparing for her daughter’s first birthday party last year, she wanted it to be memorable. So Ms. Primis, 35, ordered a buffet of child-friendly foods; decorated the tables with toys, coloring books and bubbles; and bought a gigantic pink Geronimo balloon on Etsy.

She even baked an ombré-colored smash cake from scratch. Predictably, the 15 toddlers in attendance smashed the cake and created a huge mess. But neither Ms. Primis nor her friends seemed to mind.

When the chaos mounted, they just ordered another round of beers.

Instead of cramming guests into her 800-square-foot apartment, Ms. Primis invited everyone to Frankford Hall, a sprawling beer garden in the Fishtown neighborhood of Philadelphia. “My daughter’s birthday was as much a celebration of us finishing our first year as parents as it was about her,” said Ms. Primis, an editor at Philadelphia magazine.

“No one was getting sloshed,” she said.

Across the country, German beer gardens are booming, and as they proliferate in both gentrifying neighborhoods and city parks, they’ve become a go-to destination for family outings, play dates and toddler birthdays. On weekend afternoons, many transform into Gymboree-like spaces with multiple brews on tap.