Crossbow Herbicide would be best applied to the cut stump after cutting the trees down and will not actually kill mature trees without doing so.
Crossbow Herbicide is a vegetation management product which means it is not very selective, it will kill almost anything. Although it will not harm a tree when used at recommended levels if it gets on the base of the tree, it will harm a tree if you spray Crossbow on the foliage. The required spray volume will increase substantially if the brush exceeds 5 feet in height. Brush over 8 feet tall is difficult to treat efficiently. Large brush or trees may be controlled better by basal or mechanical methods.
Crossbow should not harm established trees but may damage younger trees if applied directly to them.
Crossbow Herbicide is not labeled to kill/control evergreen trees. That being said it is recommended to keep applications outside of the dripline of desirable trees and avoid any contact with foliage.
In order to kill a tree, you would get the best results cutting the tree down to a stump and treating the fresh cut stump directly. If the trunk diameter is less than 6-8 inches, then you could potentially do a basal bark treatment with Crossbow Specialty Herbicide.You would mix 1.25 to 5 ounces per gallon of solution, mixing in diesel No. 1 or 2 or kerosene, then spraying the basal part of the tree up to a height of 15-20 inches off the ground. If you do not need this much product, then could also use Fertilome Brush Killer and Stump Killer.
Crossbow is a vegetation management product which means it is not very selective, it will kill almost anything. Although it should not harm a tree when used at recommended levels if it gets on the base of the tree, it will harm a tree if you spray it on the foliage.
Holly shrubs would need to be treated like trees, in which case you would cut the shrubs down to stumps and then treat the fresh cuts. Crossbow Herbicide is labeled for the control of most kinds of unwanted trees. On page 5 of the label you can find directions on how to use for conventional basal bark and stump applications.
Very small quantities of spray, which may not be visible, may seriously injure susceptible plants; however, Fir and Cedar trees are not listed on the label as either tolerant or suseptible. We recommend to avoid overspray or spray drift to ensure the trees are not affected.
Please review the Avoid Injurious Spray Drift section on the Crossbow Herbicide prodcut label.
Yes, the magnolia could absorb the Helena Crossbow Herbicide once applied as it stays in the soil for up to 1 year.
