Thurnscoe resident Frank Hill never expected the six inch plant he bought in a sale to have grown into the monster that it has.
Frank, 85, of Westfield Crescent, has always been a keen amateur gardener and took advantage of Wath Garden Centre's closing down sale last year by buying a few unknown plants.
Whilst some have emerged and added something to his garden, this one stands proudest and even taller than the former milkman.
"I've been involved with gardening for years but I haven't seen anything like this before," he said.
"I just bought some small plants in pots and never expected anything like this to grow but it has and I'm quite pleased with it. I think it's a lovely plant.
"The spike has only come out of the top of it this year and parts of it are ever so sharp."
The Royal Horticultural Society confirmed to the Chronicle that plant is known as the Variegated Spanish Dagger, a flowering yucca, and that it is native to the states in south eastern USA.
Spokesman Guy Barter said: "They are not uncommon but often only flower at long intervals, in a hotter than usual summer and, being a sun and warmth lover, it cannot be that common or floriferous north of say Rugby, so well done to the grower!"
Frank is satisfied that he made an excellent purchase on the day of the sale. He added: "I'm over the moon to find out what it is and it's funny to think that I only bought it by chance."
