From their event page: 

Let’s grow a more sustainable neighborhood together! Bring your bike or scooter to join Southwark School’s Rolling Rodeo and then dig in the dirt with us to get our school garden ready for spring planting.

Join Southwark School in South Philly to get our garden ready for the spring planting season. We’ll also have make-and-take stations to build birdhouses and herb planters. Bring your bikes and scooters to join the the Rolling Rodeo with stations to decorate your wheels, an obstacle course, and safe riding lessons.