To read the QR codes on the tree signs in the park, you must have a smartphone equipped with a camera and a QR code reader app. If you do not have already this app download a QR code reader/scanner app. It is easy and most QR readers are free. Open the app and center the QR code within the square outline on the screen. Try to steady your hand while you center the QR code in the square. Depending on the app you use, the page linked to the URL stored in the QR code or directions to open the link to the page will show on the screen of your phone. The page has information on the tree you are looking at.