Crabgrass prevention without fertilizer

Asked April 10, 2019, 10:57 AM EDT

What, if any, product(s) do you recommend for pre-emergent crabgrass prevention without fertilizer and where can I find it (them)? I live on a lake and want to stop the turfgrass fertilizing to minimize runoff. I am frustrated that the garden stores (Bachman's, Menards, Home Depot) seem only to carry pre-emergent crabgrass preventer with fertilizer. If I am better off to use those products, don't be afraid to say so, but please advise as to why.

Ramsey County Minnesota

1 Response

Thanks for the question. You are to be commended for being concerned about fertilizer run off. It can be a very serious problem. With respect to your primary question, the simple answer is "yes", there are pre-emergent herbicides that do not contain fertilizer. Here are some sites that describe such herbicides:

Preen is perhaps the pre-emergent herbicide most often used. Its biggest drawback - though this is true for all pre-emergent herbicides - is that grass seeding cannot be done until three or more months have passed since application of the herbicide.

If you want to avoid the use of chemicals in pre-emergent herbicides, corn gluten is often cited as being an effective alternative. However, there does not seem to be consensus on this point. See the following:

The most important thing to keep in mind is that a pre-emergent herbicide must be applied before crabgrass seeds start to germinate. They will do so once the soil temperature reaches about 55 degrees. The seeds germinate over a period of 5 to 7 days once the soil is at this temperature. Although a snow storm is pending, temperatures over the next few weeks will be in the 50's. Bottom line: now is the time to apply your pre-emergent herbicide.

Good luck!!