Though sunset maple trees, often referred to as 'Red Sunset', are prized as the most successful red maple cultivar, issues may still arise. Problems such as pests and diseases typically attack weakened maples. Maintain vigorous trees through proper care for continued enjoyment of your home garden sunset maples' vivid fiery fall color.
Sunset maples are vulnerable to leaf scorch that results in the discoloration of leaves. Look for leaves that appear as though burned with fire with the display of a yellow or brownish hue and dead tissue. Scorch leads to the overall diminished health of your tree and is often caused by contaminated soil, excessive exposure to wind or sun, inadequate watering or the presence of a separate disease caused by fungi or bacteria. Verify that your tree's soil is healthy and receives adequate water. If you suspect this is not a maintenance problem, contact your local county extension agent or a licensed professional for diagnosis and assistance.
The most widely observed type of scale problem on sunset maples is the cottony maple scale (Pulvinaria innumerabilis), according to the University of Florida IFAS Extension. Scales are pests of maple trees that create severe infestations on leaves and twigs. Scales are "sucking bugs" that remove sap from plant parts, resulting in diminished health, branch dieback and death in extreme cases. These tiny, ovular pests display light-green bodies that become brown during maturity with the addition of a fluffy white mass of eggs, according to the Virginia Cooperative Extension. Prevent this problem with the application of dormant oil during the end of spring.
Woolly alder aphids (Paraprociphilus tessellatus) are pests that infest sunset maple trees. Displaying fuzzy white bodies, aphids measure 1/16 to 3/8 inch long, according to the Clemson University Extension. Though aphids are not a prevalent problem for sunset maples, when they do appear, they suck tissue fluid from leaves resulting in curling and defoliation. Control this problem by releasing natural predators such as lady beetles that hunt and kill aphids. Find natural enemies in garden supply catalogs or online. For severe cases, use an insecticide with the active ingredient esfenvalerate. Spray on tree foliage where aphids die through direct contact. Reapply every week to 10 days as needed.