Schulzie / Getty Images
Weeds in the lawnmay start innocently enough as a stray patch of dandelions or clover.
Before long, they erupt, and you have moreweeds than lawn.
Applying weed killer keeps weeds in check or stops them before they start.
Schulzie / Getty Images
Late spring and fall are other good times to apply weed killer to grass.
“Using a pre-emergent with fertilizer helpskill weeds like crabgrassbefore they infest your lawn.”
Pre-Emergent vs. Post-Emergent
Pre-emergent weed killershalt the growth of weed seedlings and prevent weeds from growing.
Post-emergent weed killers are applied to weeds after they have begun growing.
Want more gardening tips?
But timing and temperature are important for effectiveness.
Also, there is a vital difference between pre- and post-emergent weed killers when applying them to grass.
In fall, apply the product when soil temperatures are around 70 degrees.
For example, crabgrass germinates when the soil temperature reaches around 58 degrees.
This means that the pre-emergent product must be applied before soil temperatures reach the 50s.
“Post-emergent herbicides are classified as selective or non-selective in nature,” Palmer says.
University of Georgia Extension.
