There are a number of insect threats known to attack ornamental trees within the garden. To control this threat, gardeners can use systemic granule insecticides. These offer gardeners proper protection for their trees throughout the season and additional control over where, when and how much pesticide is used within the area. This control helps avoid overdosing plants or causing irreparable harm to the garden by misuse of insecticides.
Systemic insecticides are designed to work in a different manner from traditional insecticides in how they kill and control insect threats. Traditional insecticides are applied directly onto the outer surface of the plant, killing or repelling insects away from the area. This is dangerous because precipitation and winds can easily carry the poison off of the plants where it is needed. Systemic insecticides are applied to the ground and are absorbed through the roots of the plant.
Systemic granular insecticides are protected from the elements -- unlike traditional sprays, which can be carried off by wind or rain. Also, systemic insecticides are carried throughout the entirety of the plant. This protects all areas of the plant, not just the leaves. Lastly, systemic insecticides can be introduced before signs of damage or infestation even begin to occur.
Gardeners can purchase a variety of different types of systemic insecticides. Granular insecticide bonds to the rainfall at the base of the tree and then is absorbed directly over time. Concentrated insecticides must be mixed with water before application. Premixed insecticides are more convenient, but less cost effective.
Systemic granular insecticides rely on a number of factors. The plant must absorb the insecticide and distribute it throughout the tree before it becomes effective. Also, the chemicals must penetrate the root zone before they can be introduced to the plant. Any factor coming between these two processes can leave the tree unprotected.
According to the Iowa State University Department of Entomology, gardeners should be aware that granular insecticides are not encouraged. They are not as effective as other insect control systems and are overly toxic to the environment.
The active ingredient within systemic insecticides is dependent on the type purchased. Some may use the chemical known as dinotefuran, while other companies use acephate or imidacloprid. Generally the results are the same, except one may effect particular insects that others do not.