We know that Crabgrass will start germinating with a 24-hour soil temperature average of 53-55 degrees, measured at a depth of 2-4 inches. Because our area temperatures vary widely in the River Valley and Northwest Arkansas, the exact date can vary. This generally begins to happen by April 1st.
Due to the structure of the product we use, we normally begin applying the pre-emergent in January through late March. The product – being made mostly of Carbon molecules – will primarily be degraded by soil microorganisms, which will consume the Carbon molecules as food like with any other organic matter. Therefore, with temperatures in the 40s and 50s (or lower), the loss of product is very minimal when applied In January through March.
We do get some warm periods during this time and we’ve seen Crabgrass germinate early. However, with the inevitable follow-up freeze we normally get during this time, the young Crabgrass gets “frozen out.” With the abundance of weed seeds, this process just waits for temperatures to rise again. Luckily, you would have a control product waiting for the event.
Once the Bermuda and Zoysia in our area begin to break dormancy, the product will do its job by limiting competition for nutrients and sunlight. It will also be time to give the more desirable turfgrass its first feeding of the year with a balanced product to promote strong growth.
A good lawn care program will factor these considerations in to help promote a healthier greener and more weed-free lawn. Give us a call today to help craft your 2020 lawn care strategy!