A team led by Graham Stone at the University of Edinburgh carried out the study by surveying 60 meadows planted in Edinburgh, Bristol, Leeds and Reading. City parks teams and local schools planted and looked after each site.
The research, published in the journal PLOS ONE, found a significant contribution early in the year comes from weeds such as dandelions and buttercups, which means leaving some of these to flower is likely to be important to early-spring pollinators. Rough hawkbit, wild carrot, common poppy, black knapweed, corn marigold and dandelions were among the highest-performing plants. At some times of year a single flowering lime tree can produce as much nectar as a wild flower meadow covering 300sq m, it added.
Lead author Damien Hicks said: "Flowers vary enormously in the amount and type of useful food that they produce, and when it is produced. The results show that perennial plants can produce up to 20 times as much nectar and six times as much pollen. This could be used to help design habitats aimed at boosting the pollinator community."
City of Edinburgh Council head of parks, green space and cemeteries David Jamieson said: "We welcome these research results as they clearly show how as a local authority we can significantly improve the biodiversity where most people live, work and play simply by changing the way we maintain our urban parks and gardens."