In Oregon everything has that special patina uh... rust. Be sure to wear gloves, some rusts can cause tetanus. Same from working in horse manure..I recycle horse manure a lot in my garden. my vet said its always a good idea if working around manure or oxidized metals . Rust is a bacteria and to be sure your up to date on tetanus or booster. Rust is not toxic to plants it is naturally in soils which gives it a distinctive reddish color.
The fencing will make a great trellis. Recycling is always a great way to go. Good luck.
