Ubiquitous urban plants, frequently labelled as "weeds," are the most appealing to pollinating insects, according to an eight-year study. Common ivy's autumn blooms, rich in pollen and nectar, received the most visits from insects, including bees and butterflies.
The study, part of the UK Pollinator Monitoring Scheme, found that ivy received 22 visits by flying insects per 10-minute count. Hogweed was a close second with 20 visits, followed by buddleia, bramble, knapweeds, and thistles, which averaged 14 visits each.
Jo Milborrow, butterfly monitoring officer for Butterfly Conservation, highlighted ivy as an important resource for breeding holly blue butterflies and nectaring commas and red admirals. She recommended growing ivy due to its status as the number one plant for pollinating insect visits.
The survey, run by the UK Centre for Ecology & Hydrology (UKCEH) and the Joint Nature Conservation Committee (JNCC), also indicated a decline in hoverfly numbers. Their abundance and total number of species recorded across Britain decreased by approximately a third over the past eight years.
Conversely, solitary bees increased in one survey, while honeybees, beetles, and flies (excluding hoverflies) also showed increases. This suggests that gardens, where most of the survey took place, may offer a refuge for some pollinators.