Fruit tree growers have grafted trees for centuries. Now tomato growers are getting into the act. Grafting sounds simple. Just take the top of one tomato and attach it to a different root stock, in this case, one called Mighty Mato. While commercial tomato growers have used grafted tomatoes for years, in Asia and here, they haven’t been available to the home gardener. The thinking was that they were too vigorous in the home garden.
Why would you pay extra for a grafted tomato? Because, not only are they especially vigorous, they are resistant to soil-borne diseases and much more productive.
The rootstock, named Super Natural, is a hybrid of two wild tomatoes. They have been crossed to provide for more fruit and resistance to tobacco mosaic, verticillium and fusarium wilts and nematodes. We usually don’t have to deal with aggressive nematodes on our tomatoes in this area. We do have to deal with the wilts, however. The grafted plants are also less affected by wild temperature swings, the kind of weather Minnesotans are used to dealing with.
Grafted plants have been tested in gardens in almost all of the country and Canada and have produced tomatoes not only earlier, but often, right up until killed by frost. They are also less apt to fade in drought, something we know about, too.
You can expect more than 50 varieties of grafted tomatoes to be available this year. If you plant tomatoes in a pot, stick to the cherries. Even then, the recommendation is to plant only one plant in a 20-gallon pot or larger. These tomatoes have a heck of a root system. Sun Sugar, Yellow Pear and Sweet Million are three that you may already know. Two new ones are Bumblebee pink and Bumblebee purple. They have striped fruit.
Most of the plants will be nondeterminate plants. That is, they keep growing all season. A few heirlooms to look for are Big Beef, Pineapple, Mortgage Lifter, Black Krim, Brandywine and Cherokee Purple. A new variety Indigo Rose is a purple tomato rich in anthocyanins, the chemical that makes blueberries blue and so good for you. There is at least one determinate tomato available, the kind that fruit all at once than stop. It’s called Defiant and is even blight resistant.
These new plants need a bit different care. Don’t plant them too deep. The graft must be above the soil line or the top will rot off. The big, wide roots need more room than regular tomatoes. Once the plant is 18 inches tall, snap off any suckers–the shoots that emerge from between the plant’s main stem and side branches. When the plant is 2 feet tall, take off the lowest branches and leaves to promote good air circulation around the base of the tomato. This is one tomato that must be caged or supported. If a vine gets on the soil, it will root and reduce your crop. Be very careful to keep the interior of the plant from getting too thick as this can allow funguses a nice place to set up shop.
Since these plants must be produced by hand, they are going to be more expensive. However, if you want to be hip deep in fruit this summer, let the moths out of that purse and buy a few of them.