Magnolia Scale

Asked September 6, 2018, 2:39 PM EDT

Hello- I was wondering if you could help with a question re treatment for magnolia scale? Our tree’s infestation became obvious just this year at the end of June. We were told to apply an oil to keep the bugs down (which we did), keep it well watered and then do a systemic in August. Is this the right time to do the systemic drench for our area? Thanks so much, Midland, MI (Larkin Township)

Midland County Michigan magnolia scale

1 Response

Hi. Unfortunately this is not the time to use a systemic, early May is the time for drenches. The eggs of the scale hatch in late Aug so the spray should be done in late Aug or early Sept followed by a second spray ten to fourteen days later. The only time insecticidal sprays work is when the insect is in the crawler stage. (Now) The oil should be applied in March before the buds open. Controlling magnolia scale is very challenging! The treatments you use are to kill the crawlers. It is important to keep your tree in good health by irrigating and even pruning out heavily infested branches.