Problems after overseeding

The lumps of soil could possibly be worm casts.

 

What did you top dress it with?

 

Thankfully we're all different! I'm sure that others hate some of the things that I love, but we garden for ourselves first!

I'll need to sort mine out next year and I'll be begging your advice then

 

Top soil from B&Q. Made sure it was dry, cut the grass short, overseeded the lawn then raked the topsoil over it. The seed germinated fine and came up thick and lush but after a few cuts it started thinning out and was left with these clumps of soil. I fertilised approx 2-3 weeks after reseeding. By week 6 it showed signs of thinning out. It's almost as if it germinates then dies back leaving the clods of lumpy thick top soil behind. It's so thick and wet I can't rake it out. Whenever I rake the grass it keeps pulling out the new shoots so I try to avoid raking it. It's as if it can't get any root establishment. I've been wondering if it's because I've been over fertilising so the lawn is depending on being fed rather than relying on it's root system. I'm only guessing here and probably grasping at straws. Whenever I cut the grass the clippings are very dark green and stain the bottom of my boots. I don't know if this is a clue but I've also spotted the odd few mushrooms (don't know what they're called) in the lawn. Don't know if that indicates a problem.

 

Got rid of the moss by hand using a spring tine rake. Didn't use any moss killers as I've had issues with that stuff before being too aggressive and damaging my lawn so just went at it by hand. After removing areas of moss I reseeded it and threw a fine layer of topsoil over it to protect the seed and also help even it out. After it had germinated and been cut a couple of times, I decided to fertilise it using Evergreen Cut&Feed. That stuff that greens up in 3 days. The lawn had already been professionally fertilised 2 months prior by a lawn expert but I thought a bit more would help it green up better as it was still not as green as would have liked. Then following a few more cuts and about 3 weeks later the problems started with thinning out and dying back so I stupidly went and bought some more cut&feed and put that down about 2 weeks later meaning it had been fed 3 times in 4 months. This time I managed to burn the grass. Thankfully all but one patch seems to have recovered but my grass is so limp and weak. Rather than being hard stalks that stand up straight it's more like a rug or fur and when I walk on it, it flattens down and leaves footprints in it and it's really easy to uproot.

 

It's nothing to do with the mushrooms, and it's probably nothing to do with fertilising (except for the burns).

As JWK says, It think the topsoil top-dress is the problem here. Pure topsoil (especially cheap stuff) can go really claggy, especially if laid on thick. It also probably hasn't meshed with the previous soil layer, just creating a carpet which the grass has rooted into, but then can't go any further, so doesn't grow any more and can be just pulled up.
Decent top dressing is usually at least 60% sand, to keep the soil open and to help the roots breathe.

What I think you need to do is get it hollow-tined properly. Either rent a machine or get in a lawn man to do it for you. Then rake the cores off.
Then I would brush in a layer of horticultural sharp sand into these holes (NOT builders sand, or any other fine sand). This will put a well-drained crust into the top layer and help the top layers of soil meld together. I would lightly over-seed it again, and then just leave it for the winter. The frosts and worms will do the rest.
An iron treatment late winter may help keep any new moss growth down, but apart from that you just need to let the grass find it's own way.

Good luck!

 

Done a video.

 

Had a look.

The blobs you are describing look like worm casts. They are a good thing. Just brush them out on a dry day.

The rest of my advice stands. It doesn't look like anything out of the ordinary. A proper aeration, a decent sharp sand top dress and a whole load of patience will sort it out.

 

I am trying Pam but its been 2 years since I started getting this lawn right and i'm getting a bit frustrated with it now. I don't expect overnight results but I do expect to see it improving over time but it seems like its one step forward for 3 steps back. Looks like its gonna be another year before its right and i'm running out of money for grass seed. I've spent almost £100 already reseeding this lawn for it to look no better than it was when I started. In the mean time i'm gonna lay off the fertiliser and any chemicals that may be stressing it out.

 

Been out for a closer look today and it definitely not worm casts. It seems consistent with the topsoil idea. I think what's happened is the seed has germinated into the topsoil which isn't making good contact with the original earth so the new shoots are being washed (or mowed) out. Thing is,it's all over my lawn as I reseeded quite large areas and even where there's grass growing I can feel lumps under it when I walk on it. What can I do about this? Does it need rolling down so it makes better contact? Not sure it will just brush out. How about soaking it in? Tried that already when it was dry and it just made a muddy mess. I'm worried that in time it will all need digging out and I just can't afford to renovate my entire lawn.

 

As I said above, you need to get it properly aerated, brush in a layer of sharp sand and leave it over the winter.
You've got a full coverage of grass. You just need to sort out the soil and the existing grass will find it's own way.