How Can I Control Tree-Of-Heaven?

Do you want to try controlling Tree-of-Haven with the chemical control method?

Do you want to control Tree-of-heaven with foliar sprays?

Do you want to control Tree-of-heaven with the cut-stump application?

Do you want to try controlling Tree-of-Haven with cultural control methods?

Do you want to control Tree-of-Haven with root barriers?

Do you want to try controlling Tree-of-Haven with biological control methods?

Postemergence applications are most effective after the leaves are fully developed and when the plant is actively growing. Late summer or early fall applications are often the most effective. All leaves and stems should be glistening following foliar herbicide application. However, coverage should not be to the point of runoff. Generally, a higher rate of herbicide is required to control mature or resprouting trees. However, too high a rate may kill the conducting tissues in the plant before the herbicide reaches the belowground buds.

Cut-stump treatments are most effective during periods of active growth. Stumps of trees should be cut close to the soil surface. Immediately after cutting, herbicide should be applied with a paintbrush or with a plastic squeeze bottle. Delaying application will result in poor control. For small stumps, completely cover the cut surface. For large stumps, it is only necessary to wet the cambium (the outer ring of wood, next to and including the bark). Treatment solutions should contain 25% triclopyr or 50% glyphosate from the high concentrate solutions.

A hatchet or machete can be used to cut (hack) partially or completely around the trunk of a mature or resprouting tree, using downward strokes to flare out (frill) the bark and cambium. Apply triclopyr, imazapyr, or glyphosate undiluted into the frill or hack marks. If hacks are used, one hack per 3 inches of stem diameter is generally adequate. As with cut-stump treatments, similar root-grafting injuries can occur with stem-injection treatment.

Root barriers can delay or reduce the growth of roots into areas where they are not wanted. A root barrier may consist of a hard wall of thick plastic or fabric impregnated with herbicide, such as Biobarrier. Such products may last four years or more in the landscape. However, no type of root barrier gives complete control. Eventually, roots will grow under or through the barrier and upward toward the soil surface.

Burning is not effective for controlling mature or resprouting trees. In many cases, burning can increase the population of these species. Grazing by goats can provide control in small areas. Goats have been shown to vigorously feed on resprouting vegetation. As with mowing or cutting, grazing would need to be repeated over time to eventually control the resprouting plants.

Biocontrol is not an option for the management of Tree-of-heaven. Biological control agents, such as insects or diseases which might attack the rootstock of an undesirable plant, are not yet available for the control of any urban woody species. Because some of these plants are desirable ornamentals in many areas, there would be considerable opposition to the introduction of biological control agents.

Mechanical techniques like hand-pulling or hoeing are rarely effective by themselves for the control of mature or resprouting trees. However, under some conditions, mechanical methods can control smaller trees. For example, hand-pulling, digging, or hoeing can be used to remove small trees or roots located in a yard or near houses. Saplings can also be pulled using a weed wrench tool. These procedures should be done in early spring or late fall when the soil is moist and the roots are easily removed.