Herbicide Damage to Trees
March 5, 2013
Written by A.J. Thibodeaux, ISA Certified Arborist with Preservation Tree
Herbicides for weed control in lawns have become an integral part of landscape maintenance. Chemical weed control is often perceived as more economical and efficient than hand or mechanical cultivation. Such Weed & Feed products are commonly used by homeowners and if mis-used, can be very damaging to trees. Most weed control products will affect broad leaf plants, which include trees.
Factors affecting the severity of herbicide damage to trees include rate, timing and frequency of applications. Applying Weed & Feed products at a rate that exceeds label directions is common among DIY home owners. Over-applying herbicide results in higher levels available in the soil to be taken up by your tree; increasing the level of potential damage.
Timing of application is also critical. Applying Weed & Feed products while the tree is actively growing its new spring leaves is the worst time to use herbicides. Damage in early spring can affect tree health for the entire growing season.
Most healthy trees can usually tolerate one proper application of Weed & Feed per year with minimal impact. However, multiple application in one year and/or applications made year after year can reduce tree health and vigor to a point of decline and eventual death.