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Mar 
2013 2012 
How a dormant oil spray will help eliminate tree pests

It’s officially spring, which means the flowers will be blooming and the pests will be working hard to damage your fruiting and ornamental trees and shrubs. Because several pests become active in spring, it’s important to make sure you use a treatment with a dormant oil spray to stop these pests at their most vulnerable stage. The following are just a few reasons why it’s important to get a dormant oil treatment:

  • They are selective and environmentally friendly
  • They help prevent certain pest outbreaks when applied properly
  • Individuals of the problem pest are all in the same life stage, such as an egg or larva, making them easier to target
  • Pests are easily accessible
  • Most natural enemies (insects and mites that prey upon pests) are not yet active, and so their populations are not harmed

How does a dormant oil spray kill pests?The most common dormant oil is petroleum-derrived, and may also be referred to as horticultural oil, superior oil, supreme oil, paraffinic oil, and other names. This term describes a class of high quality oils formulated for agricultural use. Other oils, such as vegetable-derived oils, can also be used for a dormant spray. Any oil applied in early spring should be mixed with water to a concentration of 1.5 to 2 percent for best results. The same oil product may be applied in the summer, but should be mixed to a concentration of no greater than 1 percent to prevent plant injury.

Oils kill pests primarily by smothering, and work best on soft-bodied insects. Insects require oxygen to live, and oil plugs the insect’s air-exchange system, causing slow suffocation. Oil works best on insect and mite eggs just before they hatch because their oxygen requirement increases.

Common pests of woody plants that can be targeted with a dormant oil spray include many aphids, European red mite, rust mites, leafroller caterpillars, peach twig borer, scale insects, shot hole borer, apple mildew, apple scab and coryneum blight.

When is the best time to get a dormant oil spray?

There is not an exact time that applies to all pests. For some pests, the dormant oil spray should be applied while the buds on the plant are still tight (3 to 4 weeks before they typically start to swell). The time to spray for most other pests on trees is anytime during the period between bud swell and leaf emergence (i.e. when flower buds are exposed and/or when less than 1/2 inch of the leaf is exposed). At that time, insect and mite eggs begin to hatch, caterpillars emerge from hibernacula (overwintering structures), and other overwintering insects and diseases become active and more susceptible to pesticides.

The spray can be applied during the following range of bud stages:

  • Apples: swollen bud to 1/2” green
  • Pears: swollen bud to cluster bud
  • Peaches/Nectarines: swollen bud to pre-bloom
  • Apricot: before bloom

Keep in mind that dormant sprays are not required every year. For example if you had an aphid or peach twig borer problem last season on your peaches, then apply your delayed-dormant spray this spring. If you have had very little damage from those pests, then you could consider skipping the spray.

*Most of this post was used with permission from the Utah State University Extension.

 

 

 

 


 

5 reasons why you should aerate your lawn

The weather is starting to get better and flowers are starting to bloom, which means it’s time to get your lawn ready for the season.  And one of the best ways to get your lawn in check is to get it aerated and jumpstart a healthy lawn. The following are 5 reasons why you should aerate your lawn:

SONY DSC1. Gets air into the soil

Lawns often get compacted from foot traffic and just overall use. As a result, the soil has fewer space to breathe, and the lawn needs space to breathe and supply its roots with oxygen. By creating holes in the ground, it breaks down the soil and gives the lawn some space to loosen up the particles and allow oxygen to get in better.

 

 

 

 

SONY DSC2. Nutrients get into the soil by the roots system

As with reason No. 1, the soil needs some space to allow nutrients to get to the root system. With compacted soils, it prevents roots from expanding and interferes with drainage and the filtration of water, which disrupts the process of the roots soaking up the nutrients needed to survive. Once again, breaking up the ground with holes allows some space in the soil.

 

 

 

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3. Allows water to penetrate the soil better

Rain and irrigation water compacts the soil, reducing space for roots to grow. However, by aerating, it allows rain and irrigation water to soak farther into the soil. This will allow the root system to grow better and allow the nutrients to be soaked up better.

 

 

 

 

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4. Helps get rid of the thatch layer

If thatch is left unmanaged there can often be serious problems with lawn pests and can often cause problems with trying to maintain the overall care of the lawn. In many lawns, a thatch layer of more than a 1/2 inch will keep the lawn from soaking up nutrients, water and fertilizers placed on the lawn. By aerating, it reduces some of that thatch layer and mixes it up with some of the soil, helping soil organisms break up the thatch.

 

 

 

DSC004425. Eliminates uneven parts of the lawn from worms

Worms are a very vital aspect of a great lawn. They, too, help with filtration and the breakdown of the soil. However, with a compacted lawn, worms have little room to break through the soil. As a result, the worms can often create uneven parts in the lawn. By aerating it gives the worms more room to do their job, thus helping promote a healthy lawn.