Don't add any gypsum unless you have a current soil test which specifies a gypsum type product and how much to apply. Most people who believe they have clay have almost no real clay. They might have very hard soil, or they might have soil which mimics clay, but true clay is rare. If you don't have a brick factory nearby, then clay is even less likely. There is a test called the jar test to determine what the components of your soil are. It's easy to do. You'll need a clear glass jar with straight sides. Usually mayonnaise jars work or olive jars. 1. Fill the jar half way full with soil and take a picture of a ruler next to the jar. That will tell you how much soil you started with. 2. Fill the jar with water and a drop or two of liquid soap (shampoo, dish soap, or liquid laundry soap). Shake the jar making sure all the soil is wet. Set the jar down. 3. After 2 minutes take another picture with the ruler. (sand and rubble measurement) 4. After 2 hours take another picture with the ruler. (silt) 5. After 2 days take another picture with the ruler. (clay) The measurement at 2 minutes will tell you the proportion of sand in your soil. If you started with 6 inches of soil and have a measurement of 4 inches of material after 2 minutes, then you have 4 inches divided by 6 inches to get 67% sand. The measurement at 2 hours will give you a silt proportion. If it measures 5 inches after 2 hours then you have 5 inches of silt minus 4 inches of sand all divided by 6 inches total to get 17% silt. The rest will be clay, organic material, or very fine material. The measurement after 2 days will allow the fine material to settle but the clay will remain in suspension. The organic matter like dead roots. twigs and leaves will float. If you can see anything through the jar after 2 days, then you don't have any appreciable clay. If the water is too cloudy to see through, then you have clay. There are chemical soil softeners you can use any time of year. They are all surfactants containing either raw organic surfactants like yucca juice or aloe vera or they contain processed surfactants like sodium laureth sulfate found in most shampoos. These materials are processed much like your great grandmother did with animal fat and wood ashes to make bars of soap. Only these modern surfactants use coconut oil and sodium hydroxide, potassium hydroxide, or other similar strong bases to make the liquid form. If you want to soften your soil try this. It has worked for me and everyone who tries it. Spray your lawn with 3 ounces of baby shampoo per 1,000 square feet. Follow that up with 1 full inch of irrigation or rain water. You can measure your application of water using empty cat food or tuna cans. When the cans are full, you have applied an inch of water. Then in a week, follow up with another inch of water. A week after that follow up with another dose of shampoo and an inch of water. That should do it. After that you should notice that your soil becomes amazingly soft after you irrigate or it rains. Then after a few days the soil will dry out and firm up again. It will be just like a sponge - soft when wet and hard when dry. The one treatment (well, two) should last for years. If you want to apply more, or if you accidentally double, triple, or quadruple the application rate, that should not hurt anything. If you do this you should never even think about core aerating again.

I think I have read all the rest of your posts. Too bad this forum has slowed down so much. I'll try to summarize some points for you. Grubs are done feeding. Killing them now is a waste of poison, time, and money. Spreading Sevin willy-nilly is part of the problem with home owners and possibly one reason they took it off the market. The nature of the "trails" in your first photo make me think you have a disease that only affected the Kentucky bluegrass in your lawn. What is left is clumps of fescue. At least you have something left. The reason for mixing fescue and KBG is just in case of something like this. One problem is your are watering waaaaaay to frequently. In the hottest heat of summer I water once a week. Of course sometimes I water for 7 hours to get a full inch of water, but usually, even in San Antonio, I water 3/8 inch, once a week. With my watering system it takes 3 hours to water 3/8 inch, so take your water pressure into consideration. Use cat food cans to measure how long it takes to get an inch of water. I can almost promise that you will be surprised. Deep infrequent watering for turf has been the rule forever. I'm nearly convinced it is the inexperienced or unknowledgeable sprinkler installers who set up demonstrations who are responsible for the trend in brief frequent watering. Getting to the reason for your weeds, reread the paragraph above. Brief frequent watering is what weed seeds need to germinate. That is exactly what you are doing now. If you can give the surface time to dry out between watering, those weed seeds will not germinate. Of course Mother Nature has Her own ideas about when to water, so keep that in mind when deciding when you water. Can't you stretch a hose out with an oscillator sprinkler and water the grass? My father had an in ground system and I was the repair guy. I hate them. How much area are we talking about? I think if you overseed with Kentucky bluegrass and follow the suggestions about watering, your problems will go away next season.

Just home after 2 weeks to discover our newly laid turf was all brown even after heaps of rain. My husband went to Bunnings for advice and was given grub destroyer. I was absolutley devastated when I found out how toxic the spray was (chrorpyrifos). We have a toddler who put every thing in his mouth. We can't go outside for out least three weeks. Apparently in stays in the soil for at least 8 months!!!! Does anyone have any environmently sound and chemical free ideas to get rid of lawn grubs or even a deterrent rather than put my child at risk. I've been told they usually come back every year but I refuse to use that toxic spray again!!!!!

I had some extensive grub damage this spring too. The crows and skunks tore up the lawn to get at the European chafer beetle grubs, which are rampant in my area. Hopefully, they help curb the numbers. Be careful as to time of year that you use nematodes and other organic controls. Here, for the chafer beetle, we apply nematodes after mid July. They are not effective otherwise. I'm trying not to use herbicides, so am just handpulling weeds and managing to stay on top of them. Crab grass you will have to dig out. Then level with top dressing and overseed. Not sure where you are or if temps are getting to hot to make this feasible now. I overseeded last month and my lawn has mostly filled in.