Say a person stranded in time, somewhere in a forest wants to make brass.
He has copper, but not zinc, so he tosses a bunch of zinc-rich beans and nuts in the smelting pot with copper and prays to god that zinc sticks to it and becomes brass.
The person has iron but wants spring steel, so he tosses bunch of manganese rich spinach into the molten steel.
Question : Will either of these work?
Assume that he has access to iron, copper, gold and silver but not any other metal. The forest has all plants and trees from Earth.