Participant Preferences for the Development of a Digitally Delivered Gardening Intervention to Improve Diet, Physical Activity, and Cardiovascular Health: Cross-sectional Study

**Background:** Low fruit and vegetable intake and physical inactivity are modifiable risk factors for cardiovascular disease (CVD). Gardening interventions can improve both behaviors but have traditionally relied on in-person delivery, limiting scalability. This study aimed to gather participant input to inform a digitally delivered, gardening-focused multiple health behavior change intervention.

**Methods:** A web-based survey was delivered via Amazon Mechanical Turk (MTurk) between November 2020 and January 2021. Eligible participants were aged ≥20 years, could read and write in English, were US residents, and had at least a 98% MTurk task approval rating. A multilevel screening process excluded respondents with response inattention, poor language fluency, or suspected bots. Of 808 MTurk workers who started the survey, 91 were excluded in first-level screening and 250 in second-level screening (244 missing demographics, 8 inconsistent responses), leaving 465 participants (212 never gardeners, 253 ever gardeners). Participants were asked about interest in gardening programming, preferences for delivery modalities (1-hour expert lectures, a series of brief <5-minute videos, or in-person meetings), and what information is needed to teach new gardeners. Quantitative data were summarized with chi-square tests; qualitative data were coded using the constant comparative method and organized into intervention functions based on the Behavior Change Wheel.

**Key Results:** Overall, 76.3% (355/465) expressed interest in a gardening program, though interest was higher in ever gardeners (84.2%, 213/253) than never gardeners (67%, 142/212; P<.001). The majority (60.7%, 282/465) preferred brief <5-minute videos (64.2% of never gardeners, 57.7% of ever gardeners; P=.16) over 1-hour lectures (13.7% vs 19.8%; P=.08) or in-person meetings (22.2% vs 22.5%; P=.93). Ever gardeners had significantly higher scores on all cooking and food skills measures (mean cooking skills: 77.8 vs 68.8; P<.001; mean food skills: 106.7 vs 96.4; P<.001). Ever gardeners were also more likely to believe homegrown produce tastes better (85.0% vs 58.2%; P<.001), costs less (71.9% vs 55.7%; P=.001), and is higher quality (81.0% vs 55.2%; P<.001). A total of 871 qualitative comments from 398 participants (85.6%) were coded. The most commonly suggested intervention functions were education and training (covering garden maintenance basics, planting/harvesting, soil preparation, seed selection, pest control, and cooking), followed by environmental restructuring (social support, group interaction), persuasion (encouragement, highlighting benefits), enablement (provision of tools/seeds), and modeling (content experts, testimonials).

**Clinical Implications:** This ORBIT phase Ia study provides evidence that potential web-based learners are interested in a digitally delivered gardening program and prefer brief video content. The findings support developing an intervention that incorporates gardening knowledge and skill development, social support, and motivational elements emphasizing enjoyment and personal satisfaction rather than health benefits alone (a 'stealth intervention' approach). The next steps include identifying target behavior change techniques and pilot testing for acceptability and preliminary efficacy. Limitations include the non-representative MTurk sample and the hypothetical nature of the intervention preferences.