The 2 days of freezing weather did not help our lawns at all, but I think there may be more happening than just the cold weather. I am hearing customers finding grub worms in the lawns, flowerbeds and potted plants. I have also seen chinch bugs in lawn samples brought in for diagnosis. I would first check the lawn for insects before treating for fungus or fertilizing. If you are uncertain you can dig up a shovel width sample of soil, grass and all wrapped in newspaper or placed in a box for us to look at.
Once we determine insects, fungus or neither, it is time to think about fertilizing. Once the grass is actively growing to the point you are mowing once a week, then it is time to apply fertilizer. I always say, “you can put a bowl of food by a sleeping dog and he won’t eat till he wakes up.” The same is true for the lawn. Since we want our lawns to recover quickly and look good again, timing is key. We need to make sure it has woke up from winter dormancy.
There are also lots of weeds in the lawn. Pre-emergents such as Weed and Grass Stopper with Dimension prevent weed seeds from sprouting and should be applied in January to stop Spring weeds, but can be applied year around for weed prevention. Existing weeds can be killed with Weed b Gon hose-end spray. It is most effective applied with 3-5 days of warm weather and sunshine in the forecast and no watering or rain for at least 3 days. Also make sure you are watering slow and deep enough since we have had several months of record heat. With a little time , patience and TLC the lawns should recover and look great once again.