His executive order gives a new task force 60 days to present plans, including a location, for the garden.
He insists the new statues must be lifelike, "not abstract or modernist".
A number of US statues have been pulled down since the police killing of an unarmed black man, George Floyd in May.
Monuments linked to the slave-owning Confederacy during the Civil War in America have been especially targeted in the nationwide protests ignited by the death of Floyd in Minneapolis, Minnesota, after a white police officer knelt on his neck for nearly nine minutes.