Texas A&M AgriLife Extension Service Trunk or Treat is a free family Halloween party at Bexar County Greenies Urban Farm in San Antonio. Hosted by the Bexar County office, this trunk-or-treat event brings families together for a fall evening of costumes, candy and community fun. The urban farm is a laid-back green space, a great backdrop for an easy night out with the kids. It's free and family-friendly, so bring the whole crew, dress up, and enjoy a cozy October evening.