.vines {
    position: fixed;
    top: 0;
    width: 32px; /* width of your vine image */
    height: 100%;
    background-image: url("vine.png");
    background-repeat: repeat-y;
    background-size: contain;
    z-index: -1; /* stay behind content */
}

.vines.left {
    left: 0;
}

.vines.right {
    right: 0;
}