Generally you should bot grow in metal pots, as the metals can interact with your fertilizer.
Even though cannabis needs Fe, with a rusty bucket you have no control over dosing and an excess of iron can lock out other nutrients, resulting in mulitple-nutrient deficiency even though those elements may be present in your soil.
So transplant into nonreactive plastic.
stinkyattic Reviewed by stinkyattic on . Rust in Pots..Harmful???? Hi All I posted in indoor grow but had no responses,(not a very exciting question) so here I am. Does anyone know if using a metal pot that has rust can harm a plant? Can the iron seep into the soil? I would appreciate any input. Thanks a bunch Rating: 5