Although it produces edible olives, the African olive tree has become invasive in some areas, such as Hawaii, Australia and New Zealand. The botanical name of this nuisance plant is Olea cuspidata and it is native to the Mediterranean regions of Europe. Learning about invasive species near your home is a good defense for keeping native species from being crowded out and dominated by them. Make sure you know what the African olive tree looks like, including its seedlings, before you undertake a removal project.
Prevent the spread of this plant by not purposely introducing it to your property. Nurseries often are allowed to sell plants that have been classified as invasive, but after you learn which of these plants might present a problem in the region where you live, choose not to landscape with them.
Destroy small African olive trees by hand pulling them and chopping them up with your clippers so they don’t take root in your compost pile or elsewhere.
Apply the herbicide Garlon-4 if you discover a major infestation of smaller African olive trees on your property. Dilute this product to a 5 percent solution and be certain to follow label instructions for safety precautions in using and disposing of this chemical.
Saw larger plants to the ground with a chain saw or hand tree saw. After you cut the tree, apply Roundup or another herbicide containing glyphosate to the stump to prevent it from regrowing. Garlon-4 and Tordon RTU, used at full strength, have proven effective in killing stumps of larger African olive trees, according to Hawaii Ecosystems at Risk.
Dispose of the berries, or olives, from trees you cut by placing them in garbage bags and taking them to your landfill. You can also burn the berries to destroy them. If you leave this tree’s fruit on the ground around the area where you cut trees, it will surely sprout into more trees, which will compound the invasiveness problem of this plant.