- Photos by Jamie Lusch

Better 'old-time' favorites

When you think about grafting, fruit trees come to mind.

Graft a Red Delicious shoot onto a dwarf-apple rootstock, and a small (8- to 10-foot-tall) tree will be produced. Graft the same branch onto a "standard" apple-tree rootstock, and you will create a tree that grows to more than 20 feet tall. Though the trees are different sizes, they'll both produce the same Red Delicious apples.

Grafting also has moved into the world of tomatoes and is now a common practice in parts of Europe and Japan. Commercial fields planted in tomatoes for decades have become plagued with root disease because of the monoculture.

Some popular varieties, susceptible to specific diseases, just can't be planted in the tainted soil anymore. This limits what varieties a farmer can plant. But grafting those "susceptible" varieties onto tomato rootstock resistant to the old disease allows the varieties to prosper with no disease problems.

A group of organic gardeners on the East Coast have been grafting heirloom tomatoes onto hybrid rootstock with great success.

Old-time, open-pollinated favorites like Brandywine, Cherokee Purple and Mortgage Lifter are so tasty that gardeners have passed the seed down for generations. Those varieties of bygone years just have a better overall taste than today's hybrids.

There's nothing like a slightly overripe Brandywine, picked fresh from the vine. Bite into one, and you get the same sensation that Amish gardener did a century ago. Heirloom tomatoes have become very popular again, and the appeal is not only taste but a link to our agricultural heritage.

The downside to heirlooms is they tend to be late producers, they produce about 40 percent fewer fruits than hybrids and they are susceptible to diseases.

Grafting heirlooms onto hybrid rootstock produces the same tomato (remember the Red Delicious apple), but they grow on bigger plants, are more vigorous, they flower earlier and are disease-resistant.

Don't confuse hybrid varieties with genetically modified varieties; the two are quite different.

Last year, I ordered 100 Beaufort rootstock tomato seeds from Johnny's Selected Seeds, which has been promoting tomato grafting for a few years. Beaufort has a good reputation as rootstock, producing a strong, vigorous, disease-resistant plant that flowers early. I chose three heirloom varieties for scions (tops): Brandywine, Cherokee Purple and Mortgage Lifter.

Seeds of the heirlooms and rootstock were sown at the same time in a greenhouse in mid-February. The goal is to have the scions and rootstock be the same size at grafting time. My seedlings were transplanted into four-packs and grown in a cool greenhouse to encourage slow growth. In mid-April, when the plants were 4 to 5 inches tall and had stems the size of a drinking straw, it was time to graft (see instructions).

The results I got encouraged me to continue experimenting this year. Mortgage Lifter responded the best.

Ungrafted, "control" plants yielded about 33 1/2 pounds per plant. They put out about 47 fruit each with each tomato averaging 11.4 ounces. The grafted Mortgage Lifters yielded 54 pounds of fruit, producing 60 fruit with an average weight of 14.4 ounces.

At $3 a pound at farmers markets, a grafted heirloom plant would have generated $60 more per plant than ungrafted ones.

Cherokee Purple also performed well, the grafted plant averaging a 36-pound harvest while the ungrafted, control plant yielded just over 24 pounds per plant.

The Brandywine grafts were only slightly ahead of ungrafted plants. Each plant combination is uniquely different, and there's still much to learn.

The most interesting part of the test was grafting some Dusky eggplant onto tomato rootstock just for fun (they are closely related plants). The yield on the grafted eggplant was more than double that of Duskys grown on their own roots. I got 5-foot-tall eggplants that produced 15 mature fruit averaging 14.5 ounces.

This year, I'll be trying three different rootstocks, along with a few new combinations. Grafting hybrids onto hybrid rootstock will create "super plants."

For more information on tomato grafting and/or purchasing rootstock, see www.johnnyseeds.com.

David James has been writing about gardening in Southern Oregon for 35 years. Contact him at djames@oigp.net.

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