Steam Gardener are the native of Wooded Kingdom introduced in Super Mario Odyssey. They are the Machine Gardener who live in the Garden area of the Wooded Kingdom. They have inhabited the Wooded Kingdom since time immemorial and always have gardening on their minds.
Steam Gardeners need power to continue their work. This is shown as several steam gardeners are lined up at a charging station. One is already at the station, recharging his power, while the one at the back of the line (who waited too long) has passed out since he ran out of energy.