Magnolia Tree and White Pine problems

Asked September 4, 2017, 10:38 AM EDT

Hello! 1)We have a magnolia tree that was planted two years ago and at the beginning of this summer began developing a substance on its bark. We have done nothing about it and now it is very extensive and has attracted many many wasps. what is happening to the Tree and what can we do.(see photos) 2) 1 month ago we planted several white pines. Two of the 6 have yellow needles now. Is this under watering? over watering? (see photos)

Hennepin County Minnesota magnolia white pine horticulture

2 Responses

For the white pine, my guess is your trees are suffering from transplant shock. It did not help that you planted them in the middle of the summer (spring or fall would be better). Read here about transplant shock:
https://www.extension.purdue.edu/extmedia/bp/bp-31.html
And here about how to plant a tree:
https://www.extension.umn.edu/garden/yard-garden/trees-shrubs/planting-and-transplanting-trees-and-s...
All you can do is keep the trees adequately watered and wait and see.

The Magnolia looks to be infested with Magnolia scale:
https://www.extension.umn.edu/garden/insects/find/scales/soft-scales-deciduous/index.html
(Scroll down to get to Magnolia scale.) Scale is a soft-bodied insect similar to an aphid. It secretes a sweet substance called honeydew, which is attracting the wasps. The above link tells how to treat. Heavy infestations can kill the tree.

Thank you Dennis! Fantastic information. I have the products ordered and will get after that Magnolia Scale ASAP! As for the White Pines, our intuition was correct about not planting in the summer, but we were falsely reassured by the nursery, We will give them some TLC and hope for the best. Thank you again, Jill