Magnolia Tree Scale? Need an arborist. - Ask Extension
Hi,
I have a Jane Magnolia that's been in our front yard for about 13 years. It has a history of blooming multiple times a summer until this year. A...
Knowledgebase
Magnolia Tree Scale? Need an arborist. #580527
Asked July 16, 2019, 9:42 AM EDT
Hi,
I have a Jane Magnolia that's been in our front yard for about 13 years. It has a history of blooming multiple times a summer until this year. As of today, 7/16/19, 1 branch of the tree has leaves like it should, and the rest of the tree looks like it's early May and just beginning to leaf out, and there are white "paint" looking spots on the branches. After a quick search online, it sounds like "scale" but I don't know the treatment course, with all posts suggesting calling an Arborist. I don't have a close up of the white spots, but I do have an image of the full tree with the 1 branch unaffected.
Hennepin County Minnesota
Expert Response
Hello. I'm glad you've turned to AaEx.
There might be two different things going on with your tree. Maybe magnolia scale and something that's affecting the blooms and leaves for this season because scale won't affect leafing out and blooms until it is really bad.
I'm including a photo of magnolia scale on a branch. If that is what you're seeing on your tree, then you have magnolia scale. What I don't see in the photo is blackened branches and twigs which is called sooty mold which happens if the tree is severely infected. So, if you see what's in the photo, then you might want to get some help with magnolia scale to keep it under control. Here is the scoop on scale in general from the U of MN: https://extension.umn.edu/yard-and-garden-insects/scale-insects#soft-scales-on-deciduous-trees-86001...
Scroll down and open the section on soft scale on deciduous trees then scroll down some more and you'll find specific information on magnolia scale. The treatment involves a spray. A large tree will require some skill in application of the spray so I recommend contacting a certified arborist. Here is a link to some information on hiring a professional:
https://extension.umn.edu/planting-and-growing-guides/how-hire-tree-care-professional
It may be that your tree took a hit during that very cold snap we had in January. That probably had an effect on the flower buds which were set last summer. It may have also affected branches and their ability to leaf out. It's hard to tell from the photos if there are any totally dead branches. From my point of view, it appears that all the branches are lightly leafed out. But if you suspect a dead branch, lightly scratch the surface to see if it's green underneath. If it's green, then it's live.
I suggest you ensure that the tree gets enough water even when mother nature does not provide (and she certainly has this summer so far) until the ground freezes which is in December. See what leafs out next spring and make pruning decisions then. I wouldn't fertilize at this point, either.
Hopefully, we'll have a decent winter.
Hi,
Thanks for the info.
I’m attaching images of the white spots. They don’t look like the scale photos you sent.
interested in what you think.
Karen Newman
Thanks for the info.
I’m attaching images of the white spots. They don’t look like the scale photos you sent.
interested in what you think.
Karen Newman
Hello,
The structures on your tree appear flatter than what I'm used to seeing if it is magnolia scale. I recommend taking as small a sample of the growth from your tree and sending it to the U of MN Extension Plant Disease Clinic. Or have a certified arborist evaluate your tree. Here is the link to the Plant Disease Clinic website where you'll learn about their services, prices, and how to submit a sample.
Good-luck!
