|Shameless self promotion|
There are a multitude of free QR generators that one can use to create the graphic. QR codes can store up to 4,296 alphanumeric characters including a URL, contact information, a telephone number, and even a poem (if you read the Google Chart Tools Infographics Overview). Google provides an app for generating your own QR code. http://createqrcode.appspot.com/
Tagawa Gardens. While wandering around, I spotted a QR code on one of their seed racks. After using the bar code reader on my own smartphone, the link pulled up a YouTube video, which was developed by Tagawa Gardens staff. The video includes basic seed starting guidelines and some ideas to improve success. Of course they also promoted additional products for the gardener, which could be purchased on site of course. I thought this was a clever use of the QR code providing information to the customer and acting as the silent sales associate.