There's no known harm and toxicity of iron/copper after oxidation is extremely rare I'd imagine.

you are already eating about 10mg of rust everyday. Anyway, a little rust is a good way to be sure your soil does not have a iron deficiency. I have had large rebar trellises for several years. They do shed enough rust that they discolor the gravel in the paths between beds. Me, the family and the veggies are all fine.

Agree - iron oxide (rust) is a normal component of dirt. ;) Plants normally use iron in their growth processes and so do people.

No worries.

Dave

Thank you all very much. I feel much better.

It was said "Anyway, a little rust is a good way to be sure your soil does not have a iron deficiency."

A common belief but not true. Rust is insoluble. Plants can't use it.

A trellis fabricated from rusty welded wire reinforcing mesh (not iron, but steel), vs one built from twine-lashed bamboo canes, natural tree branches, or a naturally rot-resistant wood - such as cedar or redwood.

It boils down to a question of whether you prefer an organic or industrial garden aesthetic.

Rust is insoluble, well I wouldn't say that as mother nature takes care of her own in time and then it will be able to be used but it does take more time than most of us like.

The plants can not use it, but bacteria can, and turn it into something that is available to plants, no?

Soil color is strongly influenced by the state of it's iron. Red soil indicates well drained soil that is adequately supplied with oxygen, ie the iron is oxidized or rusted. These are good soils for many crops. Grey soil indicates waterlogged soil with reduced iron.

Availability of iron to plants is strongly influenced by soil pH. Iron is more available at low pH. That's why blueberries need low pH.

I'll take a reddish, rusted, soil any day. Particularly a red subsoil. This indicates good drainage. Often the topsoil color is dominated more by organic matter, thus the dark topsoil in high organic matter soils.

The Fruitnut