Will not leach into groundwater. However, depending on soil temperature and composition, it should last much longer. Pruning should be done with care and common sense.
Roots give trees support and sustenance, and severe pruning can effect both functions.
When in doubt, call an arborist for consultation. Biobarrier II releases only the minimum amount of trifluralin biologically necessary to control weed growth. In applications where safety is an issue, workers do not have to be exposed to traffic during mowing or trimming operations. Biobarrier II will be especially popular among transportation departments, but landscape contractors and homeowners will find it useful too.