What should be done before applying post-emergence herbicide to newly seeded areas?

Before applying post-emergence herbicide to newly seeded areas, it is important to wait until the grass or plants have been mowed 3-4 times. This approach allows the newly seeded plants to establish themselves adequately and develop a strong root system, which mitigates potential damage from herbicide application. Mowing indicates that the plants have grown sufficiently, accessing the necessary energy from their leaves to support healthy growth despite the stress that may be introduced by herbicide treatment.

The reason this practice is essential is that applying herbicides too early can adversely affect the young plants, which are still vulnerable. Successful establishment of the seedlings typically requires them to reach a certain maturity and resilience before they can tolerate the chemicals present in post-emergent herbicides. Hence, waiting until the plants are well-established and have been mowed multiple times helps in ensuring that the herbicide application is both effective and safe for the growing seedlings.