This dataset contains seed counts of Eschscholzia californica plants introduced to form experimental arrays within habitats comprising different floral cover. Data was collected in June 2015 at the Hillesden estate, Buckinghamshire, UK. Experimental arrays comprised of three E.californica plants separated by 1m and arranged in a triangular formation. A total of sixteen arrays were introduced across four 100 hectare replicate blocks, each separated by >500m. At the centre of each block, four experimental arrays were placed at 50m intervals along a 150m transect laid symmetrically across the boundary between an established wildflower patch and bare, fallow ground or grazed grassland (two arrays within the florally rich habitat and two arrays within the florally poor habitat). On each plant, the seed set was measured for flowers which were exposed and excluded from pollinators to determine the effects of habitat context on plant reproduction. The dataset was part of a larger experiment looking at the effect of floral resources on the pollination services to isolated plants.