For many, the thought of palm trees conjures images of a tropical beach with bright blue waves crashing on the shore. However, palm trees can grow in various warm locations including deserts and rain forests. When the time comes to remove an unwanted palm tree, several herbicides will kill the hardwood tree.
Used to inhibit the growth of germinating weeds, oryzalin is a preemergence dinitroaniline sulfonamide herbicide that is available at home improvement stores and garden centers. Oryzalin controls various vegetation including crops, orchids, vineyards, broadleaf, grass and ornamental trees such as palms. In the state of California, oryzalin is listed as a carcinogen and is moderately toxic to aquatic invertebrates and fish.
A selected pre-emergence herbicide, trifluralin is available in emulsifiable concentrate and granular formulations. Trifluralin is not acutely toxic and is a safer option than other herbicides to deal with unwanted palm trees. However, trifluralin can cause skin irritation, allergic dermatitis in extreme cases, and gastrointestinal discomfort and nausea if ingested. Apply trifluralin to both the soil and the leaves to increase the effects of the chemical.
According to the EPA, oxadizon is a pre-emergent or early post-emergent oxadiazole herbicide that registered for use on golf courses and other public locations. Available for purchases under various trade names, oxadiazon has been a common herbicide for vines, weeds, trees and shrubs since it first hit the market in 1978. Oxadiazon will cause skin, eyes, and mucous membranes irritation.
Before using any herbicides, always read and follow all the warnings and directions printed on the bottle. Furthermore, wear rubber gloves when working with the herbicide and wash hands with soapy water after use.
There are several methods to distributing the herbicide to the palm trees including applying it to the soil and foliage. Another option is to use a hatchet to create downward cuts around the entire tree trunk and coat the cuts with the herbicide.
Apply the herbicide to the palm trees on a calm, warm day when there is no chance of rain. Furthermore, apply the herbicide per its specific instructions on dry leaves and soil that is not muddy.
- California Native Plant Society; Drilling as a Technique for Controlling Eucalyptus, Palms & Other Exotic Trees; Mike Kelly
- University of California Agriculture and Natural Resources: Palm
- Cornell University Cooperative Extension; Trifluralin; September 1993
- Cornell University Cooperative Extension; Oryzalin; September 1993
- U.S. Environmental Protection Agency: Oxadiazon RED Fact Sheet
Amanda Flanigan began writing professionally in 2007. Flanigan has written for various publications, including WV Living and American Craft Council, and has published several eBooks on craft and garden-related subjects. Flanigan completed two writing courses at Pierpont Community and Technical College.