The population of older adults and the percentage of people living in urban areas are both increasing in the U.S. Finding ways to enhance city-dwelling, older adults' social integration, cognitive vitality, and connectedness to nature were conceptualized as critical pathways to maximizing their subjective well-being (SWB) and overall health. Past research has found that gardening is associated with increased social contact and reduced risk of dementia, and that higher levels of social support, cognitive functioning, mindfulness, and connectedness to nature are positively related to various aspects of SWB. The present study was a pilot study to examine the feasibility of conducting a randomized, controlled trial of community gardening and to provide an initial assessment of a new intervention--"Mindful Community Gardening," or mindfulness training in the context of gardening. In addition, this study examined whether community gardening, with or without mindfulness training, enhanced SWB among older adults and increased social support, attention and mindfulness, and connectedness to nature. Fifty community-dwelling adults between the ages of 55 and 79 were randomly assigned to one of three groups: Traditional Community Gardening (TCG), Mindful Community Gardening (MCG), or Wait-List Control. The TCG and MCG arms each consisted of two groups of 7 to 10 participants meeting weekly for nine weeks. TCG involved typical gardening activities undertaken collaboratively. MCG involved the same, but with the addition of guided development of non-judgmental, present-focused awareness. There was a statistically significant increase in different aspects of mindfulness for the TCG and the MCG arms. The interventions did not measurably impact social support, attention, or connectedness to nature in this small, high functioning, pilot sample. Qualitative analysis of interview data from 12 participants in the TCG and MCG groups revealed that both groups helped some participants to better cope with adversity. It was concluded that it is feasible to conduct randomized, controlled trials of community gardening with urban older adults, and considerations for implementing such interventions are delineated.