For decades it was a common feature of suburban front gardens throughout Britain, adding a touch of exoticism to more everyday native planting.

But an unfortunate association with liberal sexual practices appears to have heralded the end of pampas grass as a gardener's favourite.

Plant sellers says sales have plummeted - in no small part due to the plant being regarded as a secret signal to passersby that its owners are happy to indulge in swinging.

Many nurseries have stopped stocking it entirely, and even large suppliers have seen numbers plummet, as buyers shun the plant for fear of what it means.

Palmstead Nurseries, which sells plants to garden designers for households, commercial gardens and public spaces, says the plant has fallen out of favour.

A decade ago the firm, based in Ashford, Kent, was selling an average of 550 of the plants every year. Annual sales fell to less than 500 five years ago and are now as low as 250.

The plant is one of the least popular of the company's grass varieties, some of which are so in demand that it sells thousands of plants every year.

Nick Coslett, the company's marketing manager, said it had fallen out of fashion in part because it was seen as a signal that swingers lived in a house.