Insecticide For Japanese Maple

The dwarf Japanese maple (Acer palmatum) is an ideal alternative for gardeners with limited space who still want the stunning fall colors associated with maple trees. These deciduous, compact trees range in size and grow in U.S. Department of Agriculture plant hardiness zones 5 through 8. As with their taller counterparts, dwarf Japanese maples are susceptible to many different diseases and insects.

Diseases

1. Various fungal diseases can infect dwarf Japanese maples and these diseases, including anthracnose, leaf spot, powdery mildew, leaf blight, verticillium wilt and rot. Anthracnose causes black spots with a tarlike appearance on infected leaves and occurs in wet, humid conditions. Leaf spots are identified by the discolored, irregularly shaped spots that develop on the foliage. Powdery mildew is one of the few fungal diseases that doesn’t require moisture to germinate and spread. It causes a powderlike growth to form on buds, stems and leaves, and infected foliage will curl and distort. Rots cause leaves to wilt and fall from the branches, stunts new growth, then branch dieback occurs and the tree begins to decline.

Insects

1. A wide array of insects use dwarf Japanese maples as a host plant, breeding ground and food source. Sap-sucking insects — such as spider mites, aphids, leafhoppers and scales consume the cell content coursing through the dwarf Japanese maple. Chewing insects — such as leaf-eating caterpillars — feed on the foliage of maple trees while wood-boring insects — such as carpenterworms and flathead borers — drill into the stems, branches and trunks of the infested dwarf maple. A few common signs of a pest infestation are chewed leaves that may have a ragged edge and tiny discolored dots on the foliage. Other signs of an infestation include yellow wilted leaves, premature leaf dropping and poor plant growth.

Control

1. Pesticides can successfully control certain types of diseases — such as leaf spot and powdery mildew — and most garden insects, such as aphids, scales and mites. When choosing pesticides, try to use the least toxic option available such as neem oil, potassium bicarbonate, insecticidal soap, bacillus thuringiensis and horticultural oils. These pesticides have a low toxicity level to humans, mammals and beneficial insects. Every type of pesticide has directions recommended by the manufacturer that you should follow to increase its effectiveness and prevent harm to the dwarf Japanese maple. For example, one brand of neem oil suggests mixing 2 tablespoons of the chemical with 1 gallon of water to create a solution that works as a fungicide and insecticide. For use as a fungicide, apply the diluted neem oil to all areas of the plant at seven-day intervals until the disease subsides. For use as an insecticide, spray the dwarf Japanese maple thoroughly when insects are present and repeat the treatment every seven to 14 days.

Prevention

1. Prevention is key to the dwarf Japanese maple disease and pest free, and requires good sanitation practices and proper cultural care. Since most fungal diseases occur when conditions are humid and excessive moisture is present, prune thick canopies to allow for good airflow. Air circulating through the dwarf maple helps promote quicker leaf drying which reduces the possibility of fungal diseases. Furthermore, remove plant debris that has fallen to the ground. This decaying plant matter provides a food source and hiding place for fungal pathogens and insects. Keep the area free of weeds, which can harbor insects. Ensuring the dwarf Japanese maple is healthy and vigorous goes a long way to protecting it from pests