You can use metal containers only in shady locations, which both reduces heat and eliminates the glare that can be tough on plants. Or, line your metal containers with bubble wrap to insulate the soil and roots from the hot metal. In very hot climates, however, the metal may get hot enough to melt the bubble wrap.
In respect to this, is it safe to plant vegetables in metal containers?
The short answer to this is yes, they’re absolutely safe for gardening use. Since it requires acidity to break down the zinc coating that galvanized steel has, and most garden soils are neutral, there’s little to no impact. Plus, zinc is an essential plant micronutrient and a normal part of the soil.
Simply so, are metal pots bad for indoor plants?
Metal Attracts Heat, Cooks Plant Roots
As a result, your plant soil and roots become hotter than they should be, in many cases causing the roots to completely overheat from direct sun. This process is made increasingly worse because of the poor insulation of metal planters.