FRP/GRP/Fiberglass Solid Rods: used for plant holders/vine stake (tapered), flagpoles, curtain poles, umbrella rib, etc. Fiberglass Nursery stakes,Vine stakes, Tree stakes, Vineyard stakes, Grape stakes Fiberglass Stakes are a great compromise in strength, longevity and price. As flexible as bamboo, but won't rot. With steel-like strength, but won't rust. Unaffected by temperature and UV ...