Garden Column: Grow fruit trees with confidence

Pheromone traps are an effective strategy for controlling insects on fruit trees, including coddling moths on apples and pears.

Pheromone traps are an effective strategy for controlling insects on fruit trees, including coddling moths on apples and pears.

People tend to have a love-hate relationship with their fruit trees. The fruit they love; the work they hate.

The spraying regimen turns off home gardeners, said Steve Renquist, horticulturist with Oregon State University’s Extension Service. But times have changed. Research has resulted in easier methods of dealing with pests and diseases, from resistant trees to low-toxicity products. For years, Renquist and the rest of OSU’s Extension horticulturists have been advocating for integrated pest management or IPM, an approach using the most effective, least-toxic methods first.

When Renquist teaches classes in what he calls low-input gardening, he starts by recommending that home gardeners choose the most disease- and pest-resistant varieties. The Extension master gardeners can recommend relevant trees, as can nurseries with expertise in fruit trees.

“If you start from that point, you’ve got a much better chance of having a low-input orchard,” he said. “You don’t have to be constantly spraying for something.”

Apples and pears are the two most common fruit trees grown in Oregon because they can be grown throughout most of the state. But everyone seems to want to grow cherries, even though they’re not the easiest choice.

“Everybody has the desire to grow cherries,” Renquist said, “but after you try to grow them and keep the birds away, you realize you’re putting a lot of effort into feeding the birds. And they get a number of diseases, too, which compounds it. One of the real tortures of homes gardeners is wanting to grow cherries.”

So he advises sticking to apples, pears and, if you’re in the right areas, stone fruits such as peaches, plums and prunes. If you’re partial to figs and persimmons, by all means plant them; those fruits are almost entirely carefree.

After choosing an appropriate variety, the next step is to be vigilant about monitoring for pest insects with pheromone traps, which can be purchased from farm stores or online. The tent-shaped traps have bases smeared with a sticky substance. On the trap bottom, place a lure with pheromones that waft a scent to attract certain insects. Starting in late spring, hang the traps in the trees and check each week. If there are more than the target level of insects caught in the trap in one week, spraying with the least toxic spray is recommended. If not, knock off the ones trapped and start counting again in the new week.

On top of that, the recommendations for sprays are for low-impact sprays, many of them organic, though Renquist points out that even some organic products have risks. A good reference for disease and pest control is Extension’s Managing Diseases and Insects in Home Orchards, which has a list of cultural practices and least toxic products for various pests and diseases. For information on specific products on the list contact your local master gardeners.


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