The hybrid plants 'TomTato' are not genetically modified but entirely natural, according to the Ipswich-based horticultural firm Thompson and Morgan.
The makers even claim that the tomatoes from the plant are tastier than most shop-bought tomatoes.
Similar plants have been created in the UK, but the firm said it was thought to be the first time they had been produced on a commercial scale.
Many of these plants - created by a technique known as grafting - had been created before but taste had previously been a problem, said Guy Barter, of the Royal Horticultural Society (RHS).
More From This Section
"It has been very difficult to achieve because the tomato stem and the potato stem have to be the same thickness for the graft to work," he said.
"It is a very highly skilled operation. We have seen similar products, however on closer inspection the potato is planted in a pot with a tomato planted in the same pot - our plant is one plant and produces no potato foliage," he added.
A similar product, dubbed the "Potato Tom", was launched in garden centres in New Zealand this week.