Half tomato, half potato plant not available in U.S.

Some call it a mutant. Others call it a “Frankenstein plant.” Still others think of it as the perfect solution for a small space garden. What exactly is a TomTato? It is a plant that can grow cherry tomatoes on top and white potatoes on its roots. I first saw it mentioned in an issue of The Smithsonian magazine and wondered what it was. When I googled it, I found it was created by a British horticulture mail order company, Thompson and Morgan.

According to the company, TomTato is a hand-grafted combination of the garden tomato (Solanum lycopersicum) and Solanum tuberosum (Irish potato). Since both these plants are in the family Solanaceae or nightshades, grafting is possible. Thompson and Morgan say their “major horticulture breakthrough is all natural — no GM (genetic modification). More than 500 sweet cherry tomatoes can be produced on top with four pounds of potatoes underneath.” This unique grafted double-cropping feature has been in development for 15 years and is now available commercially, but only in the United Kingdom. It costs about $24 per 3½-inch plant. A New Zealand company, Incredible Edibles, has their own version of the grafted tomato/potato called Potato Tom.

Supposedly, both of these wonder plants can be grown indoors or out, in a pot or in the ground. If they were available, it would be important to plant the seedlings as deep as the second set of leaves, so that the graft union is below soil level. This would ensure that the potatoes develop underground and the stems are strong. The tomato/potato plant requires the same growing conditions as any tomato plant: fertile well-draining soil, minimum of six hours of sun per day, regular moisture and fertilizer.

I know many gardeners would be excited to try growing this strange plant, but, unfortunately, neither cultivated variety is available in the U.S. Although learning to graft is a possibility, I think, if it took the professionals at Thompson and Morgan 15 years to accomplish this, it might be rather difficult. Grafting splices together the upper part (a scion) of one plant, in this case the tomato, to the rootstock of another plant (the potato). This is done regularly to produce special cultivars of roses, fruit trees or grapes. With much training, practice and trial and error, you might be able graft your own tomato and potato plants.

The alternative is to wait until a tomato/potato plant is available in the U.S. and continue, for now, to grow cherry tomatoes and potatoes in the old-fashioned way.

JoAnne Skelly is the Carson City/Storey County Extension educator for the University of Nevada Cooperative Extension.