This dataset is from a UK citizen science study called the Big Compost Experiment, and includes 1) Qualitative and numerical survey data from UK citizens about their opinions and behaviours towards biodegradable and compostable plastics, food waste disposal and home composting, and 2) Qualitative and numerical data from home composting experiments carried out on biodegradable and compostable plastic materials. Data includes opinions and behaviours towards biodegradable and compostable plastics, food waste disposal, home composting methods, geographical location, observed disintegration and degradation performance of compostable plastics in home compost. Data were collected between 07/11/2019 - 30/08/2023 Full details about this dataset can be found at https://doi.org/10.5285/1e5da176-6697-46e1-bbad-d275c100e103