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The Spokesman-Review Newspaper
Spokane, Washington  Est. May 19, 1883

Grafted tomatoes prove worthy of diverse climates

The grafted Black Pear tomato plant is vigorous and productive. (Susan Mulvihill)

Gardeners love to grow their own tomatoes. But here in the Inland Northwest, that can be a challenge. Since there are about 120 frost-free days in our growing season, we have to choose varieties that mature quickly. In addition, we might have a late frost or a chilly, wet start to the season which can be frustrating.

What would you say if I told you there is a new type of tomato plant that has increased cold-hardiness, disease-resistance and higher productivity?

This summer, I’m testing just such a tomato to see if that’s a possibility in our climate. It is a grafted tomato plant from Ezra’s Organics (www.ezrasorganics.com), which is based in Portland. Ezra’s is currently the only certified organic producer of grafted tomato plants.

In mid-June, Ezra’s co-founder Ron McCabe gave me two Black Pear tomatoes: one is grafted and the other is not. This has given me the opportunity to grow them side by side and compare their performance.

Black Pear is an indeterminate, heirloom tomato that has large pear-shaped fruit. The tomatoes are purplish-red in color and said to have an intense flavor.

Both plants are growing in the same raised bed. McCabe had me prepare the soil using John & Bob’s soil conditioners (www.johnandbobs.com), to get the plants off to a good start and help them develop strong roots. I also covered the surface of the soil with a layer of red plastic mulch to increase the amount of light that is reflected up into the plants.

Anyone who has grown tomatoes is accustomed to planting the seedlings in deep holes to encourage extra root development along the stems. You don’t want to do that with a grafted tomato, however, because that would cause the grafted variety to develop roots and lose the desirable attributes of the hardy rootstock. Other than that, the grafted plants have identical cultural requirements to regular tomato plants.

So what’s all the hubbub about grafted tomatoes? According to Ezra’s Organics’ website, “the result is an extremely prolific plant without the diseases that plague many popular varieties.” The plants have a larger root system which helps promote a higher production of fruit.

McCabe explained that the rootstock they use for their plants is very cold-hardy so he expects them to perform well even in a climate like ours. Because they will tolerate some frosts, he feels they will provide a longer harvest, which is certainly very appealing.

I’ve been monitoring the growth of the two Black Pear tomatoes in my garden this summer and here is what I’ve noticed so far:

While both plants have about six main stems, the grafted tomato is 16 inches taller (62 inches) than the non-grafted one (46 inches). The grafted plant has far more leaves and all of them are larger than the other plant’s.

Each plant has a couple dozen tomatoes growing on them. Most of the tomatoes on the grafted plant are much larger, with the largest being 4 1/2 inches in diameter. On the non-grafted plant, most of the tomatoes are quite small with the largest tomato only 2 1/2 inches in diameter.

While these results are by no means conclusive at this point, I’m certainly impressed with the vigor of the grafted Black Pear tomato. When I write my final column of the season in October, I’ll give a report on how they performed. Stay tuned.

Susan Mulvihill can be reached via email at inthegarden@live.com.Visit her blog at susansinthegarden.blogspot.com for more gardening tips, information and events.