Tomato grafting is a process that is popular in the greenhouse tomato industry which is finding its way into the garden. Due to the monoculture practice of greenhouse tomato production, the soil-borne diseases that affect tomatoes tend to build up in the soil. While there are chemicals that are available to kill these diseases, they are not available to producers that employ organic methods. Grafting of plants has emerged as a way to take disease resistant rootstock and mate it with varieties that are popular, such as the many heirloom varieties.
Some of the larger seed houses are starting to offer grafted tomatoes in heirloom varieties to the home gardener. Because the process is new and somewhat labor intensive, these plants are usually offered at a premium price. The good news is that if you start your own seeds, you can make your own grafted tomato plants.
Most, but not all modern tomatoes are hybrids. Hybrids are plants that are bred from two different parent plants to develop a plant with specific qualities, such as disease resistance. A side benefit of hybridization is that the hybrid plant usually is more vigorous.
Many of the so-called "heirloom" varieties have wonderful properties such as color or flavor but are prone to the various tomato diseases. Couple this with the fact that most home gardeners are restricted by space to planting the same crops in the same space year after year and you will see that they often have the same problem as the greenhouse growers.
This is where tomato grafting comes in. Grafting is a centuries old technique that is used in the tree industry extensively to develop trees that have certain qualities. The Rose industry also uses the same technique. In grafting tomatoes, the goal is the same. A hardy disease resistant rootstock is grafted onto a tomato plant scion that may produce great tasting tomatoes, but is susceptible to disease.
As shown in the video, the process is relatively simple and for the home gardener, won't take up much time. The tools are simple and other than the clips used, are usually at hand for the gardener that starts their own seeds.
Johnny's Selected Seeds has all the tomato grafting supplies you'll need to do this. They have several different varieties of root stock as well as the clips. Our friends at Tomato Fest have one of the largest selections of heirloom tomatoes going, and there is sure to be something you like there. Try the Wapsipinicon Peach for a tasty yellow tomato that about twice the size of a cherry tomato and really tasty. It did well in our somewhat shady garden last year.
One word of caution about grafted tomatoes, however. We like to bury our tomatoes up to the first set of true leaves when transplanting them. The plants will develop roots all along the buried stem and we think this helps to discourage blossom-end rot. You can't do this with grafted tomatoes. If you bury the graft union, the scion will start rooting and the benefits of grafting will be lost.