A garden party formal dress code means "elegant but comfortable for an outdoor setting," striking a balance between semi-formal and light weight attire. For women, this includes floral dresses, lightweight fabrics, and practical footwear like block heels or wedges to avoid sinking in the grass. For men, it means lightweight suits in lighter colors, or dress pants and a button-down shirt, paired with dress shoes that won't be a problem on uneven ground.