Natural Pest Control for Gardens and Orchards

A Certified Arborist Speaks Out about Insects and Tree Fungus Treatment

Natural Pest Control for Gardens and Orchards

Reading Time: 6 minutes

Brian Eubanks knows what he’s talking about. He’s an ISA-certified arborist and horticulture consultant in Reno and Sparks, Nevada. And he wants to tell you about natural pest control. For gardens or your own orchard, organic is attainable.

“Trees and plants have been growing on their own for over 400 million years,” he says. “People need to understand how and where things naturally grow. Once we learn to work with nature, gardening becomes the rewarding relaxing hobby that millions of us enjoy.”

Brian works with Reno’s Urban Forestry Commission, a city-sanctioned group combining the University of Nevada’s Cooperative Extension and smaller groups to make the most of the local trees. Brian works with local nurseries, encouraging them to distribute information regarding pest control and adaptability for the region rather than just attempting to sell trees.

And the information is specific to region and type of tree. A parasite attacking a peach tree may not attack an apple tree, and that parasite may not be a problem within a different climate.

“Until you become familiar with and can trust a nursery, double check the information they give you. Remember, a nursery is trying to sell as much product as possible. When it comes to doing research on the internet, keep in mind that anyone can start a web page and just because it is online does not make it accurate or true. The Sunset Western Garden Guide has always been my go-to source for plant information.”

Your nursery may tell you how to care for apple trees but might not be as knowledgeable about fruit tree diseases. The best nurseries know the trees and plants that thrive in your area and what problems you may encounter. But the key is to select a local nursery with certified personnel and experience in the area.

Brian recommends also contacting your local Cooperative Extension Service for trusted location-specific information.

Brian Eubanks speaks at the Apple Harvest Festival. Photo by Joel Lippert.

Right Tree, Right Space

You can prevent many problems before they happen by selecting the right trees for your area. Natural pest control for gardens differs location by location.

“We’ve all heard that an ounce of prevention is worth a pound of cure. Well, that piece of advice is especially true with keeping fruit trees healthy.”

A proper landscape or orchard plan takes each tree into consideration. How tall will the tree grow and how far will the canopy spread? What are the nutrient and moisture requirements? Is the tree or shrub hardy for your area and how long will it take to reach maturity? Brian states that slow-growing trees are healthier and hardier.

Elements that factor into choosing the right tree include:

  • Chill hours required
  • Pollinators
  • Which root stock best for your location and soil
  • Which varieties are most resistant to diseases in your area

Chill hours are the minimum amount of cold time required for a fruit tree to blossom. Planting a tree requiring 200 chill hours up north, where more than 1,000 chill hours occur yearly, could result in frost damage to blossoms.

Don’t bring just one tree home. Bring a pollinator with it. Pollinators are an entirely different variety but can still pollinate the other tree. For instance, crab apples can pollinate fruit-bearing apple trees. Even self-fertile varieties bear more fruit with pollinators nearby.

Once you get them home, don’t plant trees too deeply. The hole should not exceed the distance from the root ball to the trunk flare. Planting too deeply can stress and suffocate roots, enabling root-borne pathogens to enter. Also, do not put rocks in the bottom of the hole. It doesn’t aid drainage as many people believe; it actually holds too much water against the roots.

Mulch your trees with three to four inches of organic material. In addition to saving water and keeping roots cooler in the summer, it returns nutrients to the soil and encourages bio activity such as mycorrhizae, earthworms & beneficial insects and microbes.

Pruning reduces limb failure, maintains health, and encourages fruiting and flowering. Brian says there is no wrong time to remove dead or diseased branches. Always use sharp tools and disinfect then before moving on to another tree or shrub.

The Healthiest Apples

One of Brian’s specialties is apple trees. He’ll tell you that apples need at least six to eight hours of full sun per day and prefer sandy/loamy soil, or a mixture of sand, loam, and clay, with a pH of about 6.5.

If you purchase your apple tree bare-root, plant it in the early spring when the soil is workable but still cool. Trees grown in a container can be planted at any time during the growing season, if you provide plenty of water.

Dwarf varieties, which reach eight to 10 feet in height, need to be staked because of their small root systems. If you want stronger roots and a smaller tree, don’t depend on dwarfing root stock. Instead purchase a semi-dwarf (maximum height ten to fifteen feet) or a standard tree (more than 20 feet) and learn proper pruning techniques to keep it small. Bonzai are a famous example of full-sized trees which remain tiny due to pruning.

Photo by Shelley DeDauw

When Apples Get Sick

Many issues affect apple trees. Apples’ most common fungal issues are scab, powdery mildew, and cedar-apple rust.

Scab (Apple Scab): Probably the most common of apple diseases, this fungus resembles a healed-over scab. You can control scab with a sulfur spray when buds begin to turn pink.

Powdery Mildew: This fungus affects many flowers, trees, and vegetables, a common problem in well-watered gardens. It resembles white or gray talcum powder. And though it thrives in warm, dry climates, it must have high levels of humidity for spores to germinate. Pruning is the best way to prevent powdery mildew in apples because it allows air to circulate around the branches. Sulfur sprays control outbreaks.

Cedar-Apple Rust: Resembling quarter-inch rust-colored blisters, this fungus can be controlled with sulfur spray.

If you seek tree fungus treatment, Brian says to bring a small sample to your nursery or Cooperative Extension office in a sealed zippered baggie.

“Nothing makes me cringe more than someone coming in the nursery waving a diseased limb!”

The most common apple-damaging insects are codling moth, apple maggot, and plum curculio beetle.

Codling Moth: Codling moth burrows from the apple’s surface into the core, leaving black excrement in the fruit. It’s one of the most prevalent apple pests. Stop the egg-laying process by trapping males before they can mate. Set the traps during blossoming and replace every eight weeks. You can also use the insecticidal virus CYD-X when eggs hatch. This natural pest control for gardens is listed acceptable by the Organic Materials Research Institute.

Once the tree fruits, stop the larvae from entering the developing apples by covering them with barriers such as cheap nylon stockings. If the larvae are allowed to infest fruit, they will then crawl into cracks in the tree bark or in littler on the ground and pupate over the winter. Catch those larvae with sticky tree bands.

Apple Maggot: Also called the “railroad worm,” this pest leaves tracks on your apples. Use baited sprays such as organically-acceptable GF-120. Or mass-trap using dark, sticky spheres, a technique which has shown incredible results avoiding damage in the eastern United States. Replace these traps when surfaces are no longer sticky.

Plum Curculio Beetle: This pest is predominantly found in the eastern U.S. and causes devastation by causing young fruit to drop and leaving scars on mature fruit. It is fairly easy to maintain with insecticides and by disposing of fallen fruit. Pyrethrins, certified organic pesticides, have a limited effectiveness and must be reapplied at three-to-seven-day intervals to keep control over bugs. Another organic insecticide, azadirachtin, is effective as natural pest control for gardens but has not been fully tested for plum curculio beetle.

Photo by Shelley DeDauw

Fewer than 5% of all insects are damaging to plants. Nature’s amazing balance ensures almost every harmful insect has natural enemies that reduce its numbers when it gets out of control. Irresponsible insecticide use disrupts that balance by killing the beneficial insects. Arborists and plant doctors can help you identify what insect may bel causing a problem. Take photographs of the damage to the plant expert, perhaps with a small specimen in a sealed bag. The expert can recommend natural pest control for gardens and orchards. Ladybugs, copper sprays, lime soaks, and pyrethrins are all examples.

The best places for information, says Brian, are local cooperative extension services, your city’s Urban Forestry Commission, the International Society of Arboriculture, and your garden center’s certified nursery professionals.

Finding natural pest control for gardens and organic orchards is very attainable with proper guidance. From selecting trees, the area where you plant, and consulting knowledgeable resources when problems occur, you can have delicious fruit without ever using harmful chemicals. Just ask your local arborist.

Do you use natural pest control for gardens and orchards on your homestead? What’s your favorite method?

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