We’re halfway through August and the temperatures are still soaring well into the hundreds. As I sit here ordering my ryegrass seed for the farms I figured it was a good time to put out a short blog on preparing your lawn for the fall.

The hot/humid weather is ideal for warm season grasses, especially with sod in Arizona and California. If you had any weak areas in your lawn you saw one of two things happen over the last couple weeks. You either saw the weak areas begin to grow in size or you saw your problem areas fill in as the stolons moved across the open ground.

If your weak areas are getting larger you should take a close look at your irrigation system. Sometimes it appears sprinklers are getting great coverage but when you put out bowls to check for water volume you often find that area is being missed. One of the most common areas for this is right in front of your pop up sprinklers. That triangular spot right below the sprinkler is the hardest spot to cover on the whole lawn. The easiest way to fix this issue is to put in a dual spray nozzle. These cost around $3-$4 and can be installed in under a minute.

Once you have your irrigation figured out and dialed in you need to decide what you’re going to do this fall with your grass. Are you going to overseed or let it go dormant for the winter? Some HOA’s will require you to overseed your lawn and other areas will allow you to make that choice. A good rule of thumb is to forgo overseeding if you have not had your lawn fully established for at least 100 days. You don’t need to start overseeding until October so don’t forget to count the next 45 days towards that number.

I suggest utilizing the rest of August to push the growth of your lawn and get any weak areas filled in by adding a little extra fertilizer. If you have weak areas larger than 8-10” I would suggest using ammonium sulfate 21-0-0 at 5 pounds per 1000 SF two times over the next three weeks. If your lawn is healthy and growing well on its own keep the fertilizer inputs even keel with 21-7-14, Soil Burst 5-15-10 ( for lawns in Arizona), or 15-15-15. A good slow release fertilizer will keep your roots strong and your grass green until it’s time to scalp for overseed. Remember you don’t want your lawn too juiced up going into overseed so only use the ammonium sulfate if you will be forgoing overseeding or trying to give your lawn an end of the season push.

For those of you that have been hit pretty hard with rain lately make sure to give your irrigation a rest. The high humidity keeps the moisture in the plant and it needs far less water than the dry days of June. There is no need to water more than every other day for 20-25 minutes during the summer monsoon season.

One additional item you may consider before overseeding is thinning out your warm season lawn with a power rake or verticutter. This will help remove excess thatch and help grow new leaves. I like to do this once in July/August and once prior to overseed.

Here are some short videos on overseeding and verticutting that I made a few years ago if you want more information.

We’re less than 2 weeks until college football is back and that means cooler temperatures aren’t too far behind!

If you have any questions, just hit the “Ask Jay” button on the top right of this page and I will help you with an answer.

Until next time,

Jay