Warning warns snakes and tree frogs hide in potted plants
A brown-and-gold-speckled snake coils on a bed of gravel, revealing an amber eye.Getty Images

A snake spotted in an ornamental tree across the continent

Scientists say frogs, lizards, snakes, spiders and other pests are spreading around the world on cut flowers and houseplants, potentially harming nature.

These "hitchhiking invaders" range from tree frogs growing out of roses in a Sheffield florist shop to snakes found in ornamental olive trees shipped to continental Europe.

Researchers at the University of Cambridge said the consignments could also contain invasive pests capable of causing serious damage to crops and the countryside.

They say there is an urgent need for improved standards as the global market for plants, bulbs and cut flowers expands rapidly.

Els Fransen Ravon A small green lizard sits on the gnarled trunk of a decorative olive tree against a pebbled background.Els Franzen Lavin

Italian wall lizards spotted on potted plants imported to Netherlands

"Adult snakes and lizards are just the tip of the iceberg," said Professor William Sutherland of the University of Cambridge. "If they get through, what are the chances that we'll find small insects and fungi - the things that are really causing the problem?"

The production of ornamental plants is growing rapidly and expanding geographically, particularly in East Africa and South America.

Dr Sylvie Petrovan of the University of Cambridge said that while regulations and border checks were in place, the rapid volume of trade in cut flowers and ornamental plants made it extremely difficult to intercept all the pests and diseases they carried.

"Even with the best of intentions, unwanted hitchhikers will still pass through customs import inspections," he said.

Five mature olive trees from the University of Cambridge are arranged in black plastic pots and are for sale at the nursery.Cambridge University

Continental snakes, geckos and lizards discovered in ornamental olive trees imported from Netherlands

The reptile expert was called to a Sheffield flower shop to identify a live frog.

He thought it was a prank but was surprised to find it was a tree frog that had arrived from Colombia via Ecuador with a rose.

Frogs, lizards and vermin are the main stowaways found in the UK.

On the European continent, many exotic reptiles and amphibians have been discovered unexpectedly, especially in potted olive trees:

Felix Verschoor Ravon A small green, brown, white and black lizard crawls on a black plastic box among the fallen leaves.Felix Fourshall Lavin

Italian wall lizard found on crate in Dutch nursery

Research published in journal biological sciencesThe research team analyzed Dutch customs records of pests found in ornamental plants in 2017-2018 and reported them to the UK Department for Environment, Food and Rural Affairs in 2021-2023.

They called for higher production standards and the collection and sharing of data on trade-specific risks.

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