Basal bark applications are used to control shrubs, canes and thickets or trees up to what diameter, and are applied to which portion of the stems?

• A. Up to 5 inches in diameter; lower 18 inches of the stems
• B. Up to 3 inches in diameter; upper portions
• C. Up to 7 inches in diameter; middle of the stem
• D. Up to 2 inches in diameter; entire height

Answer: (A)

Basal bark applications rely on applying a oil-based herbicide to the base of the stem so it can be absorbed through the bark into the plant’s tissues. This method is suited for smaller woody plants, specifically shrubs, canes, thickets, or trees up to about 5 inches in diameter. The herbicide is applied to the lower portion of the stems—roughly the bottom 18 inches—where it can contact the bark directly and move into the plant. Using this approach on larger trees or higher up on the stem isn’t the intended use and tends to be less effective.