Can you post a picture of it?

I know several ways to do these, but it depends on how the "one arm" is designed.

lazygarden (like your name!), you can see this on Amazon by googling Klaussner Parlor Chaise Lounge. I am not able to take a pic and put in message. When one is lounging, the arm is on the left side. I thought I would sew zippered closures at the back corners and velcro straps on the underside, if I choose to make this fitted and not to the floor. I slip covered a sofa bed (to the floor), with a similar scroll arm facing, using Waverly heavy cotton-and it has held together very well as I made matching welting. This like new piece is from the Lexington, KY Macy's and though it is 'mine,' DH likes it as well!