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Urban “Weeds” Prove Most Attractive to Pollinating Insects, Study Finds
By Drooid · · How we work
Core Findings from an Eight-Year Survey
An eight-year citizen-science effort by the UK Pollinator Monitoring Scheme shows that common urban plants often dismissed as “weeds” receive the highest numbers of pollinator visits. Autumn-blooming ivy topped the list with an average of 22 insect visits per 10-minute count, closely followed by hogweed (20 visits). Non-native buddleia attracted four times more butterflies and moths than other high-scoring flowers, while bramble, knapweed and thistles each averaged about 14 visits.
Methodology and Quantitative Results
Since 2017, volunteers have recorded insect activity during 10-minute flower surveys across gardens and urban green spaces. The scheme is coordinated by the UK Centre for Ecology & Hydrology (UKCEH) and the Joint Nature Conservation Committee (JNCC). Across the eight-year span, hoverfly abundance and species richness fell by roughly one-third nationwide. In contrast, solitary bees showed an increase in one survey, and honeybees, beetles and non-hoverfly flies all rose, suggesting gardens may serve as refuges for several pollinator groups.
Conservation Perspectives and Recommendations
Butterfly Conservation’s monitoring officer Jo Milborrow highlighted ivy’s dual role for breeding holly-blue butterflies and nectaring red admirals, calling the finding “fantastic.” Martin Harvey, volunteer coordinator at UKCEH, noted that participants enjoy the counting process and observe strong insect-flower associations, reinforcing the value of citizen data for guiding habitat-friendly gardening practices.
Volunteer Opportunities and Future Monitoring
The scheme invites continued public participation, with counts scheduled each year between April and September. Volunteers can submit observations via the Pollinator Monitoring Scheme website, helping track trends and inform future conservation guidance.
Verbatim Quotes
- “We already recommend ivy as a great plant to grow because it is an important resource for breeding holly blue butterflies and nectaring commas and red admirals, so the fact that this easy-to-grow native species is also the number one plant for pollinating insect visits is a fantastic discovery – we would recommend people to start growing ivy today!” — Butterfly Conservation