May 11th is National Public Gardens Day, and you can visit public gardens throughout the USA for FREE on Friday to celebrate, including the Brooklyn Botanic Garden and Queens Botanic Garden in NYC. Click here to download the free coupon for entry — which is good for an entire group of friends or family. Stop and smell the flowers at a public garden near you on May 11th. And NYC has two of the best in the world. Thanks to sister website Atlanta on the Cheap for alerting NYC on the Cheap to this freebie.