I created a toy set for kids ages 1yr to 8yrs.  It is made out of 3/4″ ply wood and the vegetables are painted with acrylic. I manufactured these via a CNC.  The box can be easily deconstructed for storage. The vegetables only fit into one hole so there is not confusing, they can also be stuck straight into the dirt. The set also includes a hollow watering can filled with little felted wool balls that simulate water so that kids can water their plants.