Answer: Scale insects can be controlled with either horticultural oil or insecticidal soap sprays. Oils suffocate the adult scales and can be applied in late winter or very early spring, whenever the air temperature is above 40F degrees. If you're really observant, you can time the application of insecticidal soap to when the immature scales hatch and begin to crawl along the stems. This is when they are still soft-bodied and most susceptible to insecticidal soap sprays. Crawlers usually emerge in late spring or early summer. As with any insecticide, read and apply according to label directions. For added safety, make sure both the plant and the pest are listed on the label before using the product.
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