Understanding exactly what you are applying and how it works will help you decide when to get out there and start your lawn care. First of all, it’s not a race. The first neighbor to unleash the spreader from the garage is not necessarily the winner, winner, chicken dinner.
When you go into the garden center and start looking at bags you see words like ‘preventer’, ‘crabgrass’, and ‘pre-emergent’.
WHAT DOES ALL THIS MEAN?
Regardless of the brand you decide to buy, the majority of first lawn applications contain a fertilizer (to make the grass grow) and what is called a pre-emergent herbicide. A herbicide is a chemical that kills plants (in contrast to an insecticide).
A pre-emergent herbicide is one that stops a plant from growing . Look at the word: pre(before)-emergent(sprouting).
HOW CAN AN HERBICIDE KILL A PLANT BEFORE IT IS EVEN GROWING?
A pre-emergent kills the emerging seed of a plant either before or right after it sprouts. So the weed killer in the first bag you put down is actually a weed PREVENTER. Weed preventers create a barrier where they are applied that blocks growth. But wait, you say. I have put this pre-emergent down before and I still had weeds in the summer. What gives? A pre-emergent will only stop weeds if they are sprouting from a seed. If the weed is sprouting from a root that stayed in the ground over the winter, a pre-emergent will not prevent it. This is common with weeds like dandelions, clover, and ground ivy. Weeds returning from established roots need a different weed killer.
So a pre-emergent only prevents weeds from seeds. The #1 big baddie of this category is crabgrass.
But here’s the thing:
Crabgrass doesn’t germinate until it’s warm. And I don’t mean the AIR temperature. Crabgrass germinates when the SOIL temperatures hit the mid 50s. And soil takes a lot longer to warm up in the spring than the air. Think of how long it takes a lake to warm up in the spring and summer. It may be a gorgeous day on the boat but if you jump in that water, you are in for a shock. Soil temperature is similar. It warms up very slowly in the spring. Crabgrass will not germinate in March in our area and might not germinate until May. Crabgrass preventers can last up to 5 months depending on the brand.
YOU’VE GOT PLENTY OF TIME.
PUT DOWN YOUR CRABGRASS PREVENTER From Late March TO MID APRIL.
There are a number of factors that influence the germination time of warm-season weeds like crabgrass. Every year is different and every lawn is different. Stop in or call to let us help you determine the best strategy for your specific needs.