How to Get Rid of Scale on Shrubs

Scale insects feed on plant sap. Their appetite can kill off branches and even entire shrubs and trees. Since they lack a separate head and are normally immobile, they are not immediately identifiable as insects. Scale insects secrete a honeydew that ants eat; therefore, ants symbiotically protect the immobile scales from parasites and predators. Therefore, eliminating ants is an indirect way to eliminate scales. What makes them hard to eliminate directly is their thick waxy armor. Fortunately this wax makes them susceptible to the slipperiness of soap.

Toothbrush
Simple Green non-toxic all-purpose cleaner

Instructions

- 1
  Purchase a mild detergent, perhaps something ecologically friendly. An example is Simple Green detergent, which needs to be water-diluted 30 to 1 for scale application.
- 2
  Dip a toothbrush into the detergent solution and scrub the scale insects manually. They should become slippery and drop off the branch. Try more solution or more concentrated detergent if they don't.
- 3
  Deter their return by occasionally (monthly) applying a horticultural soap or oil. This can be sprayed on to save time. It will still be effective. Iit's the way scales are treated in commercial groves.
- 4
  Look for new scales and apply detergent manually every 6 to 12 months, to account for the flight/migration stage of their life cycle.

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