Gardenia – Wax Scale

Q: I have a gardenia bush and have noticed some strange looking growths. They are whitish, waxy-feeling deposits on the branches. They seem to be just on the surface of the branch. What should, or can, I do about them?


A: I believe you have an infestation of wax scale. The insects suck sap from the small branches of holly, quince, camellia and several other shrubs. The waxy covering they secrete looks like bits of white chewing gum stuck to the twigs. The females (there are no males) lay their eggs in March. Tiny “crawlers” emerge in May, all looking for a spot to settle and begin drinking from their host. Control is two-fold: pick off and destroy now all of the waxy adults you can find. In June, spray the gardenia with carbaryl (Sevin) or horticultural oil. This will kill the defenseless crawlers. Practice the two controls for two years and you’ll eliminate the scale population.

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