How to Get Rid of Spider Mites in an Alberta Spruce

Spider mites are tiny, hardy creatures related to spiders and ticks. These mites commonly infect deciduous and evergreen plants and can lead to serious damage. The presence of mites in Alberta spruce is often slow to appear; damage that begins in the fall or spring may only show visible effects on the needles during the hot summer. Getting rid of these mites is a slow and tedious process that involves multiple treatments with mite-destroying agents.

Identify infestation. Check the appearance of your Alberta spruce. See if the needles are turning a dull shade of grayish-green or needles appear droopy. Look at the space between needles to see if there is a web-like appearance. All these can be indications of spider-mite infestation. Hold a white paper sheet under the suspected spot and lightly tap the branch or leaves. Check for the appearance of minute black, red or green spots that move. This is a clear indication of spider mites.

Spray the Alberta spruce with a powerful jet of water. Observe to see if mites reappear and spray again after seven-to-ten days.

Use horticultural oils like Sunspray, Volck or Scalecide during the warm months to control actively growing mites. During winter or early spring, use dormant oils to kill mite eggs. Before purchasing any oil, read the list of plants that may be harmed by the product. Check the list to confirm if it can be used with Alberta Spruce.

If the mites persist, use a pesticide, known as a miticide, intended for use with mites, . Speak to your local extension office to find out which miticide is best to use on your Alberta spruce. Accurately follow the instructions on the product label while spraying. Pay attention to spraying on the undersurface of needles where mites generally concentrate.

Repeat pesticide application. Miticides do not affect spider-mite eggs, larvae and nymphs. These can survive a miticide application and grow, and the infestation will persist. In such cases, repeat miticide spraying every five-to-ten days to achieve a greater level of control.

Spider-mite infestations are best controlled as soon as detected; control becomes more difficult when the mite populations reach higher levels.

If the spider mite population is low, find out about using natural predators like lacewings, minute pirate bugs, lady beetles and predatory mites that feed on spider mite eggs, larvae and nymphs.

Before purchasing a miticidal agent recommended by friends or relatives living elsewhere, check to see if it is legal to use it in your county.

Miticides are poisonous. Follow safety directions on product labels and keep the containers out of reach of children.