Ash Borer Prevention
- 1). Maintain consistent care of your tree. Provide the proper sun exposure and soil conditions for optimal growth as borers typically only infest weakened or stressed trees, according to the Colorado State University Extension. Grow ash trees, for example, in full sunlight and moist, well-drained soil.
- 2). Mow around trees carefully to prevent creating injury that diminishes the tree's health and creates entry points for fungi and bacteria that will further harm it. Lay a 2- to 3-inch layer of mulch around trees, leaving a mulch-free ring around the trunk. Use organic mulch like wood chips or pine needles to help protect the tree from accidental wounds from your lawn mower. Use mulch, as well, as a means of retaining soil moisture for best growth and borer prevention.
- 3). Prune your tree in a method referred to as renewal pruning for ash borer prevention, according to the Utah State University Extension. Use pruning shears to remove lower dead, old or weakened branches to encourage newer, healthier growth.
- 4). Determine which type of ash borer is sneaking into your garden, if you have seen any or dealt with previous problems on a tree. Look for metallic green bodies measuring approximately 1/2 inch in length for emerald ash borer identification. Search for moths that look like wasps with clear wings and a body length of 1 to 1 1/2 inches in length for lilac ash borer identification.
- 5). Spray the trunk and more substantial branches of your tree with a preventive insecticide within 20 days of the appearance of adult lilac ash borers. Use a chemical insecticide with the active ingredient bifenthrin or permethrin, according to the Utah State University Extension.
- 6). Apply a preventive systemic insecticide to your tree in April. Use a chemical insecticide with the active ingredient imidacloprid, according to the Ohio State University Extension.
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