What's eating my sweetbay magnolia?

Sweetbay Magnolia shares magnolia scale as its number-one pest threat. Its semi-evergreen foliage is also browsed by deer in autumn and winter, particularly in woodland garden settings. Tulip-poplar weevil can attack stressed trees. Scale is far more commonly reported and damaging than any other pest on this species.

Soft pink-white oval bumps clinging to stems; honeydew falls onto lower leaves, promoting heavy sooty mould and weakening branch growth. Target summer crawlers with horticultural oil or neem oil spray. In late winter, apply dormant oil to kill overwintered scales before crawlers hatch. Prune infested stems.

Leaves and twigs browsed from autumn through winter; young trees can be defoliated entirely by deer in areas with high deer pressure. Install tree guards or deer fencing. Apply commercial deer repellent to foliage and reapply after heavy rain.

Larvae burrow under bark near the base of trunks of weakened trees, creating gummy ooze and branch dieback. Avoid mechanical injuries to bark. Maintain adequate moisture to reduce tree stress. Remove dead wood. Apply preventive permethrin to the trunk base in spring.