While it sounds like something out of a Halloween movie, it’s not a freak of nature or even a hybrid. It’s simply a seedling tomato grafted with a potato plant, using a technique that’s been around for years.
Thompson & Morgan (Thompson-morgan.com), whose horticulturalists worked on the project for over 15 years, says the TomTato is not genetically modified — it is a hand-grafted plant, meaning that tissue from one plant is attached to tissue from another. The marriage works because tomatoes and potatoes are members of the “nightshade” family, Solanaceae, which makes them naturally compatible with each other.
In addition to potatoes, eggplants and peppers (chili and bell types) are also members of the clan. If you look closely at their flowers, you will see similarities.
The TomTato’s double cropping feature is said to be ideal for greenhouse growing and containers. Described as a “veg plot in a pot” the annual plant requires support as it grows and produces cherry-sized tomatoes.
Paul Hansord, horticultural director at T&M, said he first had the idea for the plant 15 years ago in the US, when he visited a garden where someone had planted a potato under a tomato as a joke. In an interview with UK’s “Independent”, Hansord says, “The TomTato has been trialed for several years and the end result is far superior than anything I could have hoped for, trusses full of tomatoes which have a flavor that makes shop tomatoes inedible, as well as, a good hearty crop of potatoes for late in the season.
“It has been very difficult to achieve the TomTato because the tomato stem and the potato stem have to be the same thickness for the graft to work, 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."
A similar product, dubbed the "Potato Tom", was launched in garden centers in New Zealand earlier this month.
Sold as a live plant, not seeds, the TomTato is available only in Great Britain and New Zealand. Will we ever see it in the US? “I am sure availability will spill over to the colonies this winter,” says Anchorage Daily News garden writer Jeff Lowenfels, “and we might even be able to try out the plants here in the far north next year.”
Tomato grafting is nothing new. The technique has been used worldwide in Asia and Europe for greenhouse and high tunnel production and is gaining popularity in North America. Here’s how and why it works: The base stock or rootstock are selected for their ability to resist disease infection by certain soil-borne pathogens or their ability to increase fruit yield. The upper part, the scion of the grafted tomato, is the top part of the plant and is selected for its fruit quality characteristics.
Grafting of woody plants, especially fruit trees, has been common for centuries, but grafting of herbaceous or soft-tissue plants has only become popular recently. The cultivation of grafted vegetable plants began in Korea and Japan at the end of the 1920s when watermelon plants were grafted onto squash rootstock. Since this time, this technique has spread throughout Asia and Europe. Currently, 80 percent of Korean and 54 percent of Japanese vegetable cultivation uses grafting.
The use of this cultural technique, mainly carried out for intensive cropping systems like greenhouse and high tunnel production, has moved to the Mediterranean region as well. Spain, France, Italy have all benefited from grafted tomato production as a way to reduce soilborne disease and increase crop production.
For the home gardener and small-scale farmer, the tomato is the most popular vegetable to grow. But it has a “canary in the coal mine” reputation, notoriously catching any disease or pest that comes its way. So it’s no surprise that agriculture colleges and universities around the country (Arizona, Florida, Ohio, North Carolina) have climbed aboard the grafting bandwagon. In 2009, Washington State University began vegetable grafting with three crops: tomato, eggplant and watermelon.
Johnny’s Selected Seeds (johnnyseeds.com), located in Albion, Maine, began conducting hoophouse tomato trials in 2010. Results so far show that grafting tomatoes improves production and overall crop health and vigor, and it reduces and in many cases eliminates the need to apply pesticides.
Local tomato guru, Walt Loewen, just completed Year Two of his grafting experiments, and has learned quite a bit about the art and science of grafting tomatoes.
“It’s a lot of work. Do the research, follow instructions carefully and use the right tools.”
As you can imagine, it’s difficult to learn grafting from a book, so Walt studied Johnny’s Selected Seeds’ online videos about side-grafting and put his favorite varieties, Early Girl and Big Boys, to the test. Timing is everything, and Walt likes to get a head start each year on tomato growing. Grafting though, set him back two or three weeks because the different grafts needed to heal, a step you cannot skip or hurry along in the process. “Still, I got more tomatoes than I’ve ever had.”
For next season, Walt plans to start earlier and keep refining his technique. “I’ll grow half the plants on their own stock and the other half on grafted stock. So far,” he adds, “grafting is not earth changing, but I’ll keep working on it.”
You can read Marion’s latest blog postings at http://marionowen.wordpress.com. Gardeners are encouraged to join the Kodiak Growers Facebook page. Archived copies of Marion’s weekly columns are posted at www.kodiakdailymirror.com. Contact Marion at firstname.lastname@example.org.