The present study evaluated the role of having plants at home during the confinement period as a result of the COVID-19 pandemic that deprived people of freely visiting open green spaces. Preferences concerning the quantity of the desired vegetation as well as the ways in which the COVID-19 crisis affected the change of perceptions with regard to having plants at home were also evaluated. A questionnaire, which was filled by 4205 participants, provided an undistracted evaluation of the impact of indoor and outdoor plants on their emotional welfare considering behavioural, social, and demographic variables. The emotional state of the respondents was neutral and a significant proportion expressed positive emotions. Having indoor plants was correlated with more positive emotions, and confined inhabitants allocated more time for plant maintenance. By contrast, negative emotions prevailed in respondents who related to a positive COVID-19 case, which was more frequent in females and young participants living in small houses that received low levels of natural light and had few or no plants. A few indoor plants placed in strategic positions were also preferred compared with a high number of plants. By contrast, an increased amount of vegetation accompanied by living walls was preferred for outdoor settings. Living walls were considered as advantageous for increasing indoor vegetation, but they were also associated with technical and economical hurdles.