Norma White planted the foot-long cutting in her greenhouse in May

Retired nurse Norma White, 68, planted a one foot (30 centimetre) long cutting in her Plymouth greenhouse in May.

Since then, the vine-like plant has spread through the garden of her detached bungalow and started reaching through a hedge towards a neighbour's land.

Ms White said she believed the cutting, provided by a friend, came from a watermelon plant.

I'm disappointed in the sense that I really wanted some watermelons Norma White

So far, it has sprouted leaves up to 2 ft (60 cm) in diameter but shows no sign of flowers or fruit.

A keen gardener, Ms White initially used feed and farm manure to encourage the plant's growth.

But after the first few weeks, it needed only a daily watering to continue growing at a furious rate.

She said: "I have grown courgettes and cucumbers before and when this plant was smaller it looked similar, but I have never seen anything like this.

"The rate of growth is what has fascinated me. There are so many shoots coming off it that it doesn't matter if you clip some of them off because more grow in their place.

"For foliage it is brilliant it really is an attractive plant.

"But I'm disappointed in the sense that I really wanted some watermelons."

Ms White said she would allow the plant to continue growing until August, when she plans to chop it down for compost.