Super-vigorous grafted tomatoes first appeared on Portland area retail nursery benches last spring. This year, the offerings have expanded to peppers, eggplants, melons and cucumbers, among other vegetables.
According to wholesale grower Log House Plants – the main local producer of grafted vegetables – grafted vegetables have long been grown commercially in Asia and Europe. Grafted vegetables are prized because they are more vigorous and disease-resistant, resulting in increased harvests.
What exactly is grafting? Alice Doyle of Log House Plants describes it it in this way: "The top part of one plant (the scion) is attached to the root system of a separate plant (the rootstock)." The top part (scion), of course, is the desirable fruiting tomato or eggplant variety you want – like, an oh-so-desirable Brandywine tomato or a luscious Charentais melon. The rootstock is usually an ultra-vigorous, disease-resistant type of the same plant (or a very closely related one).
Vegetable grafting is a technique that’s been used to boost productivity and disease-resistance in Asia and Europe for years but is quite new to US gardeners. It’s a wonderful idea and is actually fairly low-tech – grafting has been used with grapes, fruit trees, and myriad ornamental plants for hundreds of years. Theoretically, anyone could do it, although it takes skill with a knife and considerable expertise to know when and exactly how to do it.
There are also a few tips to growing grafted veggies. First, you have to handle them a bit more carefully when transporting and planting, to protect the graft union. For tomatoes, plant them at the same level – no deeper, or the top (scion) will root separately and the graft will be lost. You’ll also need a taller trellising system for indeterminate tomatoes, thanks to the plants’ increased vigor and heavier fruit loads.
At the Hardy Plant Society Study Weekend plant sale this past weekend, Alice Doyle gave me a grafted Brandywine tomato plan to try. It’s going in next to the Brandywine tomato I started from seed this spring. Both plants are about the same size and since I’ve been pitifully late in planting my Brandywine, and Brandywine is such a desirable, but slow-to-produce heirloom variety, it should be a good test.