This paper presents a study on smart gardens in a smart cities context, a topic that has been gaining more and more interest from the public due to the numerous problems that are felt both in terms of environment and food consumption which, due to population increase and migration towards capital cities, have become a sustainability problem as agricultural production is moving further away from the consumers thus making it harder to obtain fresh goods such as fruits and vegetables. Using IoT combined with new communication technologies such as LoRa that has low-power and wide-area network capabilities, it is possible to create systems that enhance sustainability through a more efficient use of resources while making users more involved with the plant cultivation process and, therefore, develop more empathy towards this topic and sustainability in general. Several smart garden systems and contexts in which those systems are implemented will be analyzed to understand what can be done within this research field.