Gardeners have been urged to avoid five problem plants that people always regret buying. The Hardy Plant Society, the UK's largest Specialist Plant Society, has revealed the plants people wish they hadn’t put in their gardens. All are invasive, meaning they harm the environment by overtaking habitats. Acanthus tops the list because it is invasive and difficult to remove. A member of the society described the plant, commonly known as Bear's Breeches, as “worse than bindweed or ground elder.”

In second place was Lysimachia. Also called Creeping Jenny, it is considered a vigorous plant that can also become invasive if left unchecked. The research found Japanese Anemones to be “a thug on good loam” as people said it can quickly swamp other border plants and spread at an uncontrollable rate.

Hardy Geranium are also bothersome. They are self-seeding, meaning they spread easily into other plants and grow quickly, making them difficult to remove.

This plant was also on British gardeners’ list of “desert island plants”, according to The Hardy Plant Society, meaning they would choose it if they could only pick one thing to plant, despite its negatives.

In fifth place was Euphorbia, which also spreads easily and contains latex that can irritate the skin and eyes. The plant is also toxic to livestock - it can contaminate hayfields and reduce the forage value of pastures.

"I'm in complete agreement with the first choice of garden regrets, however, having spent years ruing the day I planted Acanthus mollis in my garden as a novice gardener," said Steve Bustin, chair of The Hardy Plant Society.

"Experienced gardeners know the plants to avoid but when you see any of our 'most regretted' plants on sale in a garden centre the label gives no hint of the misery that plants might come to inflict over the coming years.

"It would be good to see some of these plants carry a 'health warning' that in some gardens (not all) they might become a problem."