Shelterbelt species for which trifluralin is registered include American elm, caragana, green ash, Scots pine and Siberian elm. Very limited foliar absorption occurs following postemergence simazine application. The usual time of application would be late fall or early spring, to a relatively weed free soil surface with limited trash cover. Weeds present at the time of application will not be controlled. Careful attention should be given to label precautions regarding the texture of the soil to be treated.
Continuous agitation is required in the sprayer tank during mixing and application.
Application is not recommended until the trees have been established for at least one year. It is rapidly absorbed by plant leaves and is rainfast 1 hour after application. Once absorbed, it causes growth to stop by blocking the production of new membranes. The leaf color change, during this process, is generally yellow to purple or red before they become necrotic. The process takes anywhere from one to three weeks for completion.