The dormant season is a good time to check woody plants for infestations of scale insects. This time of year deciduous plants are without leaves and the scale are more easily seen. If you detect an infestation, make plans to apply a dormant oil application to control them late this winter. Scale insects are easily overlooked because they are small and immobile most of their lives and they do not resemble most other insects. Many of them resemble little 'shells' which are circular to oval in outline, but some have more unusual shapes like oyster shells.
Color varies and includes white, tan and brown.
Plants that should be inspected for scales include apples, pears, other fruit trees, bush fruits, euonymus, lilac, crabapple, oak, ash, elm, lilac, maple, linden, arborvitae, juniper, pine, spruce and yew. Plants are not harmed if only a few scales are present. But populations of some scales can increase dramatically during the growing season within only a few months. Heavy scale infestations can damage fruit crops, destroy branches and even kill entire plants when repeated heavy infestations occur. This is the time of year when gardeners are eager to get out and do something in the landscape.