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Aerating and covering holes / seeding afterwards guidance needed

Hi all,

I understand that this question may have been answered many times before but I am still unsure.  I am planning on aerating my lawn for the first time but after doing so, I suspect there will be lots of holes around the garden.

1) Should I mow before aerating?
2) Am I able to fill in the holes immediately after aerating?
3) If yes to the above, should I fill with top soil or lawn dressing?
4) Can I then lay down seed immediately after?

Thanks for all of your help.


  • JennyJJennyJ Posts: 8,216
    1) Yes, it makes it easier to see what you're doing (but if it's the first cut of the season, don't scalp it - keep the blades high)
    2) Yes if you like. I tend to leave the holes because I have sandy soil and it crumbles into them as soon as it rains. I spike my grass to relieve compaction not for drainage.
    3) Depends what type of soil you have. Something sandy (lawn dressing probably is) if you have heavy soil, something more retentive is fine if you're on light soil.
    4) Yes if your weather forecast is suitable (or you're prepared to water enough to keep it moist until the seed germinates) and you actually need to overseed. If it's only a bit thin, the grass will thicken up once you get going with little-and-often mowing. Scuff up the soil surface with a rake where the grass is thin and make sure the seed makes good contact.
    Doncaster, South Yorkshire. Soil type: sandy, well-drained
  • Hi Jenny,  Thank you so much for the quick easy to understand responses.

    It is the first cut of the year so I will keep the blades high.  How do I know what type of soil I have?  I am thinking I have heavy soil but how can I determine this?  

    Thanks again, you have really helped a lot!
  • JennyJJennyJ Posts: 8,216
    Soil types - pick up a handful and feel it - info here better than I could write
    You can check here as well but it might not be accurate for topsoil if yours was brought in when the house was built.

    Doncaster, South Yorkshire. Soil type: sandy, well-drained
  • Thanks for the links, I will make sure you later on but from what I recall my soil is not sandy at all and more clay like.  If it is clay like, would it be OK if I put top soil into the holes?

    Also, once all holes are filled up I am thinkin of throwing seed over the lawn.  Should I tread on the seed afterwards to force contact with the soil or is it better to put another layer of top soil over the seeds?
  • JennyJJennyJ Posts: 8,216
    Clay soil is something I don't have experience of, but someone who does will no doubt be along soon. I think it would probably be better to mix sharp gritty sand with the topsoil. Grass seed doesn't need a thick layer of soil over it, just raking into the surface. Treading carefully over it might help with contact but I've only heard of that being done with wildflower meadow seed.
    Doncaster, South Yorkshire. Soil type: sandy, well-drained
  • Dave HumbyDave Humby Posts: 1,142
    A light top dressing over the seed is a good idea and also gives some protection against the next challenge which is pigeons and doves! Just a dusting though.

    You need to have the seed in contact with the soil to germinate so after broadcasting you can apply a light spraying with the hose which will get the seed started and also push it down on the soil. Don't blast it around though or the seed will all end up in the low spots. Alternatively, if you have a mower with a roller you can push this over the lawn (when dry) and that will push the seed into contact with the soil. Do NOT have the mower running for obvious reasons. 

    If you do have heavy soil you can leave the holes to self-seal over the top which they will do with regular foot and mower traffic. Sports turf use this technique often.
  • Thanks Dave and Jenny.  

    Yes, watering heavy NEVER works for me as all the seeds end up in one corner!  Pigeons are a real challenge which is why I want to cover the top.  You mentioned a light top dressing over the top.  In the past I have put light top soil over the top, should I go for top dressing instead as I assume it is more sandy?
  • Dave HumbyDave Humby Posts: 1,142
    I don't think the type of top dressing you use is hugely important. Top soil can tend to clump a little whereas something like Lawn Seeding Soil tends to be a bit more granular which fills the hollows easier and also has nutrients targeted to help the seed get a kick-start in life. It's a little more expensive than regular top soil. 
  • Ahh got it, thanks Dave and Jenny.  Last question (I think) is regardin aerating the lawn.  I have never done this and was wondering if it is good enough to simply use a garden fork?  Any suggestions for a low cost solution?
  • JennyJJennyJ Posts: 8,216
    I just use a fork. Mine's a border fork because it's more suited to my height and strength but a full-size garden fork will do the same job. It's quite hard work (I'm a bit puny, you might find it easier) but I usually only do the areas that get walked on a lot and compacted. I think I've read somewhere that a hollow tine aerator is better because it doesn't compress the sides of the holes, it takes out cores, but when I tried one it didn't work for me because it wouldn't wiggle past all the pebbles like a fork does (and it was just as hard work). It would probably work better on nicer soil.
    Doncaster, South Yorkshire. Soil type: sandy, well-drained
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