This article details the making of traditional cordage/rope. Although commonly made from synthetic materials or specific plants such as manila hemp, hemp, linen, cotton, coir, jute, and sisal, it is possible to make cordage from a variety of plants. Self-made cordage is useful for low important tasks/tasks that require little tensile strength (ie espaliering, ...)
http://www.ssrsi.org/sr2/Indust/ropenet.htm http://www.instructables.com/id/Make-rope-out-of-dead-plants----with-no-tools/ http://www.wildwoodsurvival.com/survival/cordage/men79/index.html