What should be avoided when considering the application of preemergence herbicides?

When considering the application of preemergence herbicides, it is essential to avoid using them when laying sod. This is because preemergence herbicides are designed to inhibit the germination of seeds, including weed seeds, by creating a chemical barrier in the soil that prevents seeds from sprouting. When laying new sod, the sod itself is made up of grass that needs to establish its roots and grow. The use of preemergence herbicides during this process can hinder the establishment of the newly laid sod, as it may also inhibit the germination of seeds present in the soil that are meant to aid in the successful root growth of the sod.

The other options do not present the same level of concern when it comes to the application of preemergence herbicides. Applying them in the spring or fall is generally acceptable as long as the application is suited to the type of weeds you are targeting and follows the specific guidelines for the herbicide being used. Using them with wetting agents may enhance their efficacy by improving soil penetration but doesn't pose the same risk as laying sod.