When I first heard of grated tomatoes, I thought it was a marketing ploy. Why graft a plant that only lives one season then dies? It turns out, though, that grafted tomatoes address real problems that market farmers have. Since these tomatoes are now finding their way into the consumer market, I will discuss why they are being produced in this post. Next post will discuss how they are grafted.
Tomato growers battle a range of diseases to grow the tomatoes we eat. Grafting helps combat verticillium wilt, fusarium wilt, corky root rot, root knot nemotodes, bacterial wilt, tomato mosaic virus, and tomato spotted wilt virus. Research is ongoing about the ability of grafted tomatoes to withstand early blight, late blight, and blossom-end rot. Even the best sanitation in the world cannot keep all these diseases at bay when a farmer uses the same field year after year. Since farmers only have a limited amount of land, they have to use it whether they have these problems there or not.
The University of Ohio is studying grafted tomatoes. So far, they out produce regular tomatoes. Why? The rootstock is usually a variety that is very disease resistant. Unfortunately, the tomatoes it produces are pretty nasty. But when good tasting tomatoes are grafted on the rootstock, you get a disease resistant plant that produces good tomatoes. This is being touted as a way to revive some heirloom tomatoes that have trouble resisting disease but taste good. They also add to the genetic diversity of the tomato crop.
Grafting has been used for centuries for fruit trees. Asian vegetable growers began using it in the 1920s to combat a range of diseases. They grafted watermelons onto gourds or squash rootstock. This was such a success that today 81% of Korean vegetables and 54% of Japanese vegetables are produced on grafted plants. Several countries in Europe also graft vegetables.
At present, the only place I have seen grafted tomatoes for sale to the general public is Territorial Seed Company. The company that supplies them with the tomatoes, Log House Plants, has a very thorough discussion of grafted tomatoes and links to research on them.
Next post I will discuss how to graft your own tomatoes if you want to do that. In the meantime, if you want help with gardening, take a look at my book.
For more help gardening, buy my book, “Preparing a Vegetable Garden From the Ground Up.” Available in print or eBook, this book walks you from choosing the site of your garden all the way through what to do after the harvest. Buy a copy for yourself or a friend today!