help with sod on top of hard clay

[newhomeowner]

Hi all,

Newbie here.

We built a new home in Raleigh last summer, and didn't know to improve the clay soil before good quality TTTF sod was laid.

Now that the weather is heating up, I'm already seeing areas struggling. When I try the screwdriver test there are areas where it is really hard. I''ve been doing some reading here and it seems like I have the following options (I've already made sure clippings are left on the grass):

1. spread baby shampoo every month - does this really work?

2. come the Fall, top dress with compost before we overseed. I know many people don't believe in aeration, but does it make sense to aerate to 6" to given the compact clay soil? Maybe aerate - top dress - seed?

Many thanks for the advice!

[PSU4ME]

How much lawn are you talking?

As for your two suggestions, they are good ones. The aeration will help break the clay and allow the water, compost (nutrients) and air to get in there.

The baby shampoo, look at the blsc recipe here, will also help. I believe the sls in blsc will help chemically unbind the soil so it’s a good addition. Maybe someone can comment on the frequency as I’m guessing you could get pretty aggressive with it if it’s needed.

[newhomeowner]

The yard is a total of 10k sq ft, most at the front and a smaller amount at the back.

I bought a long moisture meter and have been very surprised by the results. We had 0.7" of rain 2 days ago, and some areas register completely dry already. Other areas a very wet still. The weather since has only been in the 60's - 70's. I have a slight hill, but I wouldn't expect that to make a huge difference?

How deep does that shampoo affect things? Will it improve the drainage of the clay underneath the sod too? I'm worried about the grass surviving the summer heat as there are already bare patches. Will the shampoo help with that?

Kicking myself for not insisting they till the clay before they laid the sod to help with the compaction.

I noticed some products that claim to help with root development - are they worth it?

Any advice greatly received!

[newhomeowner]

Bumping this... anyone have any advice please?

[andy10917]

You might want to dig a hole with vertical sides, and see what a profile of the soil looks like. You could also fill the hole with water once you've seen the profile, See how long it takes to drain to empty. That will teach you a lot about the makeup of the soil. Post the results.