A new study from the University of Cambridge warns that wildflowers planted in cities could harm bees by passing on toxic metals. Researchers found that plants like clover and bindweed can absorb lead, cadmium, and arsenic from polluted urban soil. When bees drink nectar from these flowers, they may suffer memory loss and even death. The study focused on Cleveland, Ohio, but experts say this problem may exist in many older cities with a history of industrial activity.
Flowers in Cities Carry Hidden Dangers
Wildflowers are often planted to help bees and other pollinators. But the soil in urban areas can be unsafe. The new research shows that some flowers absorb harmful metals from the ground. These metals move into the nectar that bees collect.
The study tested wild plants growing in empty lots around Cleveland. This city has a long industrial past and more than 33,000 vacant spaces. Flowers such as chicory, clover, and wild carrot grew naturally in these areas. When researchers tested the nectar, they found high levels of lead and other dangerous metals.
Which Plants Are Most Affected?
The study found that chicory absorbed the most metal, followed by white clover, wild carrot, and bindweed. These are plants that bees love to visit. But if the soil is dirty, the nectar can become toxic.
Bees exposed to even small amounts of these metals can lose their ability to remember where flowers are. This makes it harder for them to collect food and return to the hive. Over time, this can lead to fewer bees and damage to the whole ecosystem.
Scientists Call for Better Soil Testing
Researchers are asking cities and gardeners to be more careful. They say it is still good to plant flowers for bees, but only if the soil is safe. Many urban areas have soil that is still contaminated from old factories, roads, and buildings.
Dr. Sarah Scott, who led the study at the University of Cambridge, explained:
“Wildflowers are essential for pollinators, but so is soil health. Check the land’s history and test the soil if possible before planting.”
A Warning for Growing Cities
As more cities focus on planting wildflowers and creating green spaces, this study offers a clear warning. Without checking soil safety, even good actions can cause harm. Pollinators are already at risk from pesticides and climate change. Toxic metals add another threat.
This research encourages urban planners and communities to include soil checks in their green projects. Healthy soil means healthy bees, which are vital for growing food and keeping nature balanced.
What This Means for Gardeners and City Planners
Anyone planting flowers in a city should first learn about the area’s history. Was it near a factory or old building site? Does the soil look clean? A simple soil test can check for lead, arsenic, and other harmful elements.
Community gardens, schools, and public parks can all help bees. But it’s important to make sure the soil supports life instead of harming it. Taking this extra step can protect pollinators and make green projects more successful
Bees are key to pollination and food production. Helping them is important, especially in urban areas. But this study shows that planting wildflowers without checking the soil may do more harm than good.
