People tend to have a love-hate relationship with their fruit trees. The fruit they love; the work they hate.
But times have changed. Research has developed easier methods of dealing with pests and diseases, from resistant trees to low-toxicity products. For years, Steve Renquist, a horticulturist with Oregon State University’s Extension Service, has advocated for integrated pest management, an approach using the most effective, least-toxic methods first.
“Everyone wants to minimize spraying,” Steve says. “Low input means it’s better for the people eating the fruit, better for the environment in the backyard, better for the safety of the pets and family running around out there. It’s a pretty easy sell.”
Steve recommends home gardeners choose the most disease- and pest-resistant varieties. Extension Service master gardeners can make recommendations, 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,” Steve says. “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 people often grow fruit trees that are hard to maintain.
“Everybody has the desire to grow cherries,” Steve says, “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.”
He advises sticking to apples, pears and, if you’re in the right area, stone fruits such as peaches, plums and prunes. If you’re partial to figs and persimmons, 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 are sold at 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 bugs trapped and start counting again in the new week.
“Scientists make it pretty simple,” Steve says. “That’s the beauty of the system. They determine the number of insects to look for. It’s something hard and fast you can follow. You’re applying on the basis of need rather than the basis of prevention.”
On top of that, the recommendations for sprays are for low-impact sprays—many of them organic—although even some organic products have risks. For information on specific products, contact your local master gardeners.
Steve stresses that home gardeners need to rotate sprays—three per season is best—to avoid resistance.
Another strategy is to apply low-input dormant oils before trees have budded out, which smother the eggs and larvae of many insects and decrease problems down the line.
Of course, keeping your trees in top shape is key.
“A lot of it is the health of the tree,” Steve says, “well-timed sprays, good pruning, good fertilization. You really can have fruit produced with far fewer inputs than people lead you to believe.”