Carol, The best time to prune a magnolia is after it blooms. Pruning a mature magnolia is not recommended as large cuts heal slowly and encourage disease. However, dead or awkward limbs should be removed. I would hire a certified arborist to work on this tree. A product called AzaMax is a broad spectrum pesticide that will kill scale. Check out out on Yardener.com. Best And Happy Yardening, Nancy.
Large Flowering Magnolia Has Scale And Needs Pruning
Question From: CALIFORNIA
Q: My parents have a very old (60+yrs) very large flowering magnolia that has had scale for years. Spraying by a pest control company hasn't helped. At the end of Aug. I used Bonide systemic from Navlet's Garden Center as directed on the bottle. I was told it would take months to show improvement. Is there anything else to do for this tree? It flowers beautifully every spring and is full of folliage, but the scale makes a sticky mess underneath. This tree is in San Jose. Also it needs to be pruned. When is the time to prune it? After the leaves fall off? Thanks for any help.