Is the soil black gumbo clay?

Yeah

Love to help you out, but I need a little more information.

• Where do you live?
• What kind of grass do you want to use?
• Is there shade from trees or buildings across the yard?
• Will the yard be used for sports or for dogs?
• Do you want the entire 4,000 square feet to be lawn or do you want some garden space for shrubs, or specialty plantings?

So generally, the best way to soften hard soil is to grow stuff in it and let the roots loosen it up. Beyond the roots there are different types of fungi which will also help to soften the soil. What they need to get going is food, water, and a good environment. The food comes from organic fertilizer, water from water, and the environment comes from really deep watering.

If you look at the ingredients on a bag of organic fertilizer you'll find a lot of animal feed like soybean meal, alfalfa meal, corn meal, etc. You can visit your local feed store and buy one or the other of those for about 1/6 the cost of commercially bagged organic fertilizer. The application rate is 15 to 20 pounds per 1,000 square feet. Put that down and moisten it being careful not to wash it away. It does not get "watered in" like chemical fertilizer does. All you have to do is moisten this. I use alfalfa pellets (rabbit chow). When you moisten those they expand about a day later into greenish worms. If you walk on them or drag a hose over them, they disintegrate and become food for the soil fungi.

Watering is important for softening the soil and growing grass. For established lawn, deep and infrequent is the mantra. Deep means 1 inch, all at one time, every time you water. Infrequent means once a month in the early spring, once every 2 weeks as the temps warm into the 80s, and once a week with temps in the 90s. If you have temps higher than 100, then once every 5 days. These are general guideline, not the Bible. But in no case should you ever water an established lawn every day.

You can develop a good environment for the fungi without roots in the ground by spraying the area with...baby shampoo. Please don't stop reading; golf courses use a similar product called Cascade Plus to spray their greens and keep the water penetrating. Baby shampoo, or any other clear shampoo (from, say, Dollar Tree) works fine. The application rate is 3 ounces (minimum) per 1,000 square feet. For 4,000 square feet I would divide that by front and back or 2,000 feet at a time. For 2,000 square feet put 6 ounces of shampoo into a hose end sprayer tank, fill the tank with water, and spray it all out as evenly as you can until the tank is empty. You cannot make a mistake with this. People have tried overdosing with up to 60 ounces per 1,000 and there was no damage to the garden. What the shampoo does is reduce the surface tension of the water allowing it to penetrate deeper into the soil. Follow up the shampoo application with a deep watering of at least 1/2-inch of water. The end result is the water carries down deeper into the soil cooling it off for the fungi. You can test the softening by trying to push a screwdriver into the soil before the shampoo and after (3 weeks after). If the screwdriver does not plunge deeply or easily, repeat the shampoo and give it another 3 weeks. The shampoo treatment should be a one-time event unless you want it softer. I used it back in 2012 on my lawn then and it was still very soft after a rain when I moved out in 2015. You soil should become very soft when it rains and gradually firm up until it rains (or you irrigate) again. That is normal.

You can test the clayishness of your soil using a clear glass jar. Olive jars work great. Fill the jar half way with your soil and put a ruler up against it. Then take a picture to show what you're starting with. Fill the jar all the way with water and a few drops of shampoo or dish soap. Shake the jar long enough to dissolve any clumps or clods and set the jar down. Take another picture with the ruler after 1 minute. Then take another picture after 1 hour. Then take another picture after 1 day. After the first minute, all the sand and gravel will have settled. After one hour the silt will have settled on top of the sand. After 1 day, if you have clay, the water on top will still be cloudy. Compare how many inches of soil you had initially with how much has settled after a day. The remaining suspension of soil is clay. Most people are surprised to find they have clear water after a day which means they have almost no clay.

So with all that going on, please answer the questions I asked up front, and we can get you going on a lawn.

I would only add topsoil if I had a low spot that needed filling to stop pooling when it rains. The soil you have is likely to improve immensely

Hi sorry but I can't write a comment back it keeps deleting it when I hit the spacebar.? As for the questions it's in northern ohio there is absolutely no shade, we got outsidepride midnight kentucky bluegrass, no sports or animals and yes the whole sq foot will be used. But we have decided to just do the front yard of topsoil because the back is free and clear of debris and is a much better soil condition. Thank you very much by the way

I would only add topsoil if I had a low spot that needed filling to stop pooling when it rains. The soil you have is likely to improve immensely by using organic fertilizer to feed the beneficial soil microbes living there plus getting grass growing. The photosynthesis from the grass will provide sugars (carbohydrates) for the soil microbes through the root system and the microbes will provide plant food to the plants when the microbes are well fed and watered.

One of the problems with planting grass this time of year is that this is when crabgrass seed wants to germinate. If you use KBG sod, then you have a shot at making it through the summer without it converting to crabgrass. One thing you might do is not spend a lot of money on seed/sod this time of year and then in late August you can do this properly giving the grass ample time to develop heat resistant roots prior to summer 2024.