It appears fall is never going to arrive as we’ve hit 90+ degrees twenty-three days in a row in the Phoenix area. The nighttime temperatures have slowly begun to cool but surprisingly they have yet to fall into the optimum range to overseed. For those who may have thought they were too late to drop seed, you still have a couple weeks to get your lawn going. Most people have already overseeded their lawns so I want to give some tips to assist your ryegrass while your warm season grass continues to grow.

If you overseeded anytime during the month of October I’m sure your lawn looks absolutely beautiful right now. It’s important to keep in mind that some of your grass is probably bermudagrass that bounced back from being scalped. How could this happen you ask? With daytime temperatures in the 90’s and nights in the 70’s it has allowed for an extended growing season. Many people including our sod farms use a turfgrass regulator such as Primo prior to scalping to help keep the bermudagrass in check. While this does help with a lot of the grow back it can’t prevent everything from coming back to life. Now that the ryegrass is up and growing strong it’s also a good time to put down a first or second application of Primo or other growth regulator. These products will greatly increase the density of your ryegrass and keep the bermudagrass from growing back. Why do you want to keep the bermudagrass out? If the bermudagrass is actively growing it is preventing your ryegrass from filling in completely. This is usually first observed after the first frost and the lawn will have small quarter size dormant turf spots throughout the turf. This is not a big deal as the ryegrass will eventually fill it in but something to keep in mind.

Fertilizer on Overseeded Turf

Now that your lawn has been growing for a couple weeks you should be making a second or third fertilizer application. I suggest going with 21-7-14, 15-15-15, or Soil Burst 4-4-2. You want to keep pushing the growth of the ryegrass while not encouraging additional bermudagrass growth. Stay away from ammonium sulfate at this time of the year.

Ideally a third application of fertilizer will be applied prior to the first frost of the year. This will vary depending on where you live but sometime around Thanksgiving is a good guideline.


Once your lawn has been established from seed it’s time to drastically cut back your water. The first two weeks of growth require 3-4 mini shots of water a day and now you can get away with one. Set your sprinklers to run first thing in the morning for 10-15 minutes for the next 7-10 days. After the seed has been growing for one month reduce your watering schedule to every 3-5 days depending on rain, temperature, and need. Your lawn doesn’t actually need to be watered until it starts to show a little stress. If you walk on your lawn and the footprints don’t bounce back up then it’s time to water. You may also notice a bluish grey tint to the lawn which is another indication that your grass is ready to be watered. The winter is the perfect time to cut your water bill back and still enjoy a perfect lawn.  Check here for more year round watering tips.

Dormant Turf Maintenance

The warm fall has given your lawn a little extra life and color late in the season. I suggest applying a fertilizer with a good potassium source (last number on a fertilizer bag) to give the lawn strength over the winter. Most stores carry different types of winterizer fertilizer so you will need to check with your local nursery. For the next few weeks you can make an application of Barricade or other pre-emergent herbicides to control winter annual weeds that may pop up in your lawn. This will be applied at .5 oz/1000 SF and will give you control all winter long. Some weeds may escape the herbicide but for the most part you can expect a clean lawn all winter long.

Dormant turf should be watered every 3-4 weeks in the winter to maintain moisture but often doesn’t even need to be watered as supplemental rain will accomplish this goal.

We have more info on Fall Overseeding.  If you have any questions please let me know.