Managing urban gardens for pollinators: plant richness, abundance and origin seasonally influence flower visitor interactions regardless of the surrounding landscape

1. Private gardens contribute to a large area of land within cities. Yet, little is known about the value of private gardens in pollinator conservation in terms of their management and position within the urban matrix.2. We investigated seasonal patterns in how environmental variables influenced plant-flower visitor interactions and the network structure in private gardens. We collected plant-flower visitor data in 18 private gardens, simultaneously recording floral abundance and richness, plant origin, garden size, land use diversity and the percentage of green space surrounding gardens.3. We observed a decline in native plant abundance from June until September, resulting in fewer visits to native plants at the end of the season. This result coincided with an increase in non-native floral abundance and consequently increasing floral visits to non-native plants in September.4. Plant-flower visitor networks varied seasonally, becoming more specialised in June and September, but were not influenced by other environmental variables.5. Overall, higher floral richness and abundance within a garden influenced flower visits, independent of the surrounding landscape.6. Our results indicate that private gardens can be of great conservation value to pollinators in cities, regardless of the urban context in which they are situated. Moreover, we present evidence that non-native plants can be highly attractive to pollinators and supply resources when native plants are scarce. Overall, we show pollinator diversity can be improved in gardens by increasing floral diversity. We provide a list of attractive plants species to help inform floral plantings in gardens.