Hello,

Managing crabgrass and establishing native grasses like Little Bluestem and Side-oats Grama can be challenging, but it’s not impossible. Cool season cover crops can indeed help suppress weeds like crabgrass by out-competing them and providing ground cover that reduces the light and space available for weed seeds to germinate. More information at this link:

FS1309: Crabgrass and Goosegrass Identification and Control in Cool-Season Turfgrass for Professionals (Rutgers NJAES)

However, while cool season cover crops might reduce the presence of crabgrass, they may not eliminate it. Crabgrass is a tenacious weed that can thrive in various conditions, and its seeds can remain viable in the soil for years.

Therefore, relying solely on cool season cover crops might not be sufficient for complete eradication.

Using a pre-emergent herbicide can be effective in preventing crabgrass seeds from germinating. It creates a barrier at the soil surface that disrupts the germination process. If you choose to use a pre-emergent, timing is crucial—apply it in early spring before the crabgrass seeds start to sprout. More information at this link:

Agronomy eUpdate December 7th, 2023 : Issue 985 (ksu.edu)

For a more sustainable approach, integrating both methods could be beneficial. You can plant a cool season cover crop to outcompete weeds and follow up with a pre-emergent in the following year to tackle any remaining crabgrass seeds. This integrated weed management strategy can create a more favorable environment for your desired warm season grasses to establish.

Remember, each site is unique, and local conditions such as soil type, climate, and existing vegetation will influence the effectiveness of these methods. 

I hope this helps!