Ralph from Jacksonville, Fl writes
Pre-emergent weed products like Princep usually need to be applied when soil temperatures are lower than 55-65 degrees Fahrenheit to be effective against weed germination. After the weed seeds have warmed up, they germinate, rendering pre-emergent applications useless. There is not a specific temperature but if it gets close to 85-90 degrees it is possible that those seeds have already germinated. Please view our Warm Season Lawn Care Schedule for general timing recommendations or contact the Master Gardener with the County Extension Office for specific timing in your area.
Answer last updated on: 08/24/2021
