I would choose an insecticidal soap or summer oil, personally, because I have a pet and I don’t want to poison him or myself or any of the other critters in my yard with more toxic chemicals. I would apply it at a time that pollinators are unlikely to be around as it is nonspecific as to what insects it smothers. Test it first on a leaf to be sure that your plant will tolerate it. I would also likely do it when it is overcast.

Thanks NHBabs. I will look into those.

I gave my magnolia a soil drench of imidacloprid. That got rid of the scale.

Right after I did it noticed all the waspy kind bugs feeding on the honeydew and the little finch birds coming in to pick off the scale. I felt horrible and guilty knowing I was sending a poison out into the food chain by all the life that was attracted to the scale. At least the magnolia was not in bloom. My hope was that as the scale died, the waspy kind bugs and little birds would stop feeding on them.

That was a very strong lesson in the interconnectedness of things. I did it once and the scale has never come back. So far.

I have two 25 foot magnolias afflicted with scale the last two years. To tell the truth, I do not remember what the arborists used. Iĺl find out. One had lost half its leaves. Sprayed in fall 20, was re-sprayed this spring 21 and looks fine now.

The other has not fared as well. I honestly don t remember if it was sprayed this spring, but half itś leaves are gone and I strongly suspect the scale is back.

These are two beautiful yellow magnolias: Jane and Yellow Bird and centerpieces of my spring garden. I have no pets or kids around now. Iḿ 70 and not up for spraying big trees. My conscience bothers me a bit but Iḿ not going to let these magnificent trees sucumb to scale.

I know Iḿ rationalizing but maybe I made up for some harm by declining my neighborś invitation to join her in spraying for mosquitoes this year. We have more rain, more regularly than I can remember in all my years of New England gardening. But the mosquitoes are like being on the Gulf in Louisiana in the summer, not a suburb in Massachusetts. So I spray myself and my clothes with Deep Woods Off, 40% DEET and venture forth.

We all have to make choices, dont we?

Thanks Christopher C NC and Marie for sharing your experiences. I wish I did not ignore the problem when I first noticed it so I could have just cut off the affected branches. As I indicated above, I will first try an insecticidal soap or summer oil. Hope that works. I do have a lot of insects milling around the area so trying not to use stronger stuff.