When is a good time to apply a pre-emergent crabgrass preventer? This is what we’re telling our customers:
So we never have an “exact” date on when to apply the crabgrass pre-emergent since every season is different. We monitor the weather and soil temperatures. Crabgrass germinates when the soil temperatures are consistently 60° F degrees for 3-5 days at a 1/4″ level. Remember, crabgrass pre-emergent must be applied at least 2 weeks prior to germination for it to be effective. April 1st looks like a good target date right now but that may change depending on weather conditions. Here’s a great (real time) link for crabgrass germination and optimum times to apply pre-emergent from Michigan State University: GDD Tracker
As you may know, the best crabgrass prevention is a dense, healthy turf, but because crabgrass has a massive reproductive & survival capability, it is common to have some in your lawn. Some of you may have seen more crabgrass come up several weeks after your first application last year. To prevent that second flush, simply apply another crabgrass pre-emergent to your lawn 7 weeks after the first treatment.
Here are some helpful tips to prevent crabgrass: Apply a pre-emergent 2 weeks prior to crabgrass germination. Regular fertilization should help thicken turf along with proper watering and mowing. Water deeply and infrequently. (Light and shallow watering will encourage crabgrass growth). Do not mow more than 1/3 of the leaf blade at one time. If you mow below 2.5-3 inches (depending on the turf species) it will increase crabgrass populations.
IMPORTANT TO KNOW: If you are planning on seeding or have completed a dormant winter seeding, do not use crabgrass pre-emergent. It will likely end up killing any new grass seedling growth. There are a few options for crabgrass treatment if you have planted grass seed or plan on planting this spring. Just give us a call and we can go over the products to use. Use caution when using post emergent herbicides and ALWAYS read the label. 574-232-6811 is the number to call.
Pick your battles. You can’t plant grass seed AND apply crabgrass pre-emergent at the same time. If crabgrass was a problem for you last year and you want to treat it, apply the crabgrass pre-emergent and save your seeding for fall. That is the best time to seed anyway. (Typically around August 15-September 15 … again, every year is a bit different … Purdue explains more about seeding in their free publication – CLICK HERE).
Here’s more info from Purdue Science: Crabgrass Control
Know when to give up. If you wait until summer and you realize your crabgrass is out of control, you may as well let it go until it dies off with the first frost. There are post emergent herbicides that you can use but they are more difficult to use than the pre-emergence products, they cannot be used in the heat of the summer, are expensive, and are only effective on smaller crabgrass plants – which you probably don’t see anyway.
If you are looking for crabgrass pre-emergent + fertilizer, come see us! We have quality fertilizer in stock at great prices AND you get expert advice (the advice is free) if needed!
The weather is getting warmer so why not take a leisurely drive out to New Carlisle to pick up your sod, seed, herbicides and fertilizer. Also, don’t forget to visit us on Facebook to see all of our updates including office hours and our first harvest of the season!
We have a ton of crabgrass topics! Check out our previous blog posts that touch on the topic of CRABGRASS by CLICKING HERE.
Until next time!
The Red Hen Crew