TIMING IS EVERYTHING – TAKE CONTROL OF MAGNOLIA SCALE NOW

When small crusty bumps or patches appear on the stems and leaves of Magnolia plants, the symptom is often mistaken for some kind of fungus or other plant infection when in fact, these seemingly inanimate deformities often signify an infestation of scale insects  A minor infestation usually does not seriously affect the plant’s overall health, but a major infestation, however, can drain a tree of enough sap to seriously stress it, causing the leaves to yellow and the twigs to die back. Excess sap drained by the insects is excreted in a honeydew substance that can foster the growth of sooty mold, which will, in turn, draw ants, wasps, and other insects to the tree. The sooty mold itself is not harmful to the tree, though it does serve as an indication that scale insects are present.  Magnolia scale insects spend the winter as dark nymphs clinging to small twigs on magnolia bushes and shrubs. They begin to feed and grow in the spring. The insects mate in late spring, then the males die and the females continue to enlarge through July. The females give birth to live young (crawlers) in August through September, which then crawl about to seek a spot to feed on plant stems through the winter. It is during this juvenile crawler phase that magnolia scale insects are most vulnerable to pesticides and other control strategies.  So if you notice these crusty bumps or little crawlers on your magnolia, now is the time to take control. A variety of horticultural soaps and oils, such as neem oil will work to smother insects at the crawler phase in late summer, but they do not work on the adult insects present at other times throughout the year. However, you will need multiple applications to fully control the infestation.  You may also use chemical pesticides to kill scale insects at the crawler stage. However, once the scale insects move past the juvenile stage, their hardening exoskeleton makes them quite resistant to contact with pesticides. Thus, late summer is the best time to spray for scale—September is a traditional time to spray for magnolia scale. Apply the first spray treatment in early September and follow up with a second treatment 10 to 14 days later.   Read the full article and more about this subject at https://www.thespruce.com/what-do-i-do-for-magnolia-scale-control-2132828.  “How to get rid of magnolia scale” by David Beaulieu