Growing Grass in Hot Weather and Clay Soil

growing grass in hot weather
I live in a zone 9 planting area and growing grass in hot weather can be a real challenge. Most of the time our weather is nearly perfect, but in the summer for about a month it gets above 100F and in the winter it will sometimes freeze at night. It means that anything we plant has to survive extreme heat and freezing temperatures. Luckily the grass does pretty well with frost – our main challenge has been the extreme heat. Combine that with clay soil, no rain, and a thriving insect population, and growing a lawn can feel like a full-time battle.

But I was determined and finally came up with a lawn maintenance routine that seemed to do the trick without being too cumbersome. However, I found that I had to stick with it or stuff quickly began to die.

I also learned that your best resource is your local fertilizer store. Big box stores are great for some things, but they don’t know your region like a local store does. For example, our local store was able to sell me a grass seed mix specially designed to thrive in this area. I had tried to patch dead spots with grass seed I had bought at Lowes and had terrible luck. But when I used this stuff, it just took off and kept growing. They are also helpful if you have some dead spots and are trying to figure out what is killing your grass. Many universities also have a master gardener you can call who knows your area well. The key is to get local help.

Planting Tips for Growing Grass in Hot Weather

If your area has clay soil like ours, getting the water to penetrate the ground and stay there is going to be a huge problem, especially if you have any kind of slope. We made the mistake of having a very slight incline when we planted our grass. It was barely noticeable, but it was enough to cause big problems. The top part was always too dry and the bottom was too wet. Even though our lawn was being watered evenly, the water would just flow down the hill.

When planting a lawn in a zone 9 area with clay soil, getting it level is very important. It is also important to have adequate drains because the clay doesn’t really absorb the water very quickly and you can get a swamp.

I also wish that we had replaced more soil. We mixed in a good top coat, but it wasn’t enough. We should have gone six inches deep with the top coat.

The best type of grass to plant in this area is a hardy blend of tall fescue. It does well in the cold and the heat and stays green year round. Check with your local store and see if they have a mix they like for the area.

Watering Tips for Growing Grass in Hot Weather

Breaking up your watering into smaller cycles can help a lot with water absorption and prevent run off. So if you normally water your lawn for 15 minutes, break it up into three five-minute cycles that are spaced about an hour apart. This gives the ground time to soak it in. It is also a great way to reduce the water run off. So many people waste a lot of water when watering their front lawns. It all drains onto the sidewalk and down the road. Breaking it up keeps this from happening. Note: Just be careful not to run the sprinklers for too short of a period of time. Depending on your sprinklers, they have to be on for a certain amount of time in order to get full coverage.

You don’t want to water at night because you can get fungus, so I start my cycles at about 5:00 AM so that they are done before the sun is really up and evaporation starts to be a problem.

When the weather was over 100 F, I found that I had to water every other day or every day to keep the lawn alive. Ideally, you want to water deep with long periods in between to encourage root growth, but in the summer the clay soil just doesn’t hold the water long enough to do that. So in the winter, I try to water only twice a week, and in the summer I increase it.

Also, if the soil becomes very dry it can become hydrophobic, meaning that it repels the water. This creates a problem because you can’t get the soil wet enough to stay wet and when the summer sun hits your grass is going to wither. However, you can break the surface tension and improve absorption by adding a little bit of liquid dish soap to the water. Try adding the soap to one of those spray fertilizers guns you attach to your hose and watering a little by hand before your sprinklers start.

Lawn Mowing Tips

Tall fescue is supposed to be tall, so avoid the temptation to cut it short. In the winter it should be two inches tall and in the summer it should be three inches. The extra height in the summer helps shade the roots and protect the plant. Also, don’t use the clipping or mulch bag when mowing – leave those clippings there! Grass clippings are great for your lawn and fertilize it as they decompose.

Zone 9 Lawn Maintenance Schedule

After a couple of years of experimenting, I was finally able to develop a maintenance schedule that actually works. It has done wonders for me and some of my neighbors who started using it too. It also helped me revive the neglected lawn in our front yard. Our house was a repo, so it sat empty for a year before we bought it. The lawn hadn’t been watered or cared for in all that time. It needed a lot of TLC.

You can get far more technical and work extensive, but I tried to keep it simple and doable. I wanted a nice lawn, but I didn’t want to become a slave to it.


  • Spread a slow release fertilizer like LESCO Professional Turf Fertilizer. It releases for about 8 to 12 weeks.
  • If you have a problem with weeds, now is a good time to treat with a pre-emergent herbicide. For it to work, you have to apply it before the weeds emerge. If you wait, you are basically wasting money. If you are unsure, make a note of when the weeds start to come out this year and plan to apply the pre-emergent herbicide around the same time next year.
  • Remove any thatch from your lawn. This will help the new stuff grow once the spring hits.

Early March:

  • Aerate your lawn with a core aerator. Aeration is so important if you have clay soil. It is also important to use a core aerator that pulls up the little plugs of dirt. The ones with spikes that just leave little marks in your soil don’t really work. We always did ours by hand. My husband would water the lawn to loosen it up a bit and he figured it was a good workout. But you can also rent a bigger one if you want to. One year we paid a neighborhood kid to do it and I think he hated us after that…
  • If your soil is really bad, after you aerate is a great time to apply a top dressing, but you will want to remove the clay plugs first. I buy several bags of soil topper and spread it over the lawn about 1/4 inch thick. I then work the topper down with the back of my rake. Over time, doing this will improve the quality of your soil.
  • If your lawn is really struggling, this is also a good time to reseed. However, the best time is in October.
  • Spot treat any crabgrass or Bermuda. The best stuff to use for this is Turflon Ester. It kills weeds and controls the Bermuda grass without damaging your lawn. It doesn’t kill the roots of the Bermuda and you will have to keep reapplying it, but it is your best bet if you don’t want to kill your lawn too.


  • If you have problems with grubs or other insects, now is a good time to spread insecticide.


  • Reapply a slow release fertilizer.


  • Reapply insecticide if needed.


  • August is usually when I get problems with fungus. I have to water a lot and the weather is hot, perfect for growing fungus. So if you need it, now is a good time to use a fungicide. If you aren’t sure if your brown spots are a problem with fungus or a lack of water, you can perform a simple test to see what areas of your lawn are getting enough water. Just spread empty tuna fish cans on your lawn in various locations before one of your normal watering times. After the watering, check to see how much water is in each can. If your brown spots have less water, then it is a problem with water; if they have more, it is probably a fungus.


  • Reapply a slow release fertilizer.

Early October:

  • Aerate with a core aerator and remove the plugs if you will be reseeding or applying a top dressing.
    -This is the best time to reseed in our area. The frost doesn’t come until around January, so it gives the grass lots of time to establish itself without extreme temperatures. I typically seed any bald spots and put soil topper on top. I also broadcast some seeds if the lawn is thin and cover the entire lawn with a thin layer of soil topper, about 1/4 inch.

When you break it all up, it isn’t bad, and I found it very helpful to follow local advice that applied to our area. However, once the price of water went up with the drought, we finally decided to get rid of all our lawn. It was hard to do after all the work I had put into it, but it has been a year now and it was one of the best decisions we have made in our yard. I have saved so much time on mowing and maintenance. My only regret is now that we have cute little guinea pigs, they would have loved to munch on all our lawn. Oh well! When I get a chance, I will post some photos and details on what we did.

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