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Weeds between flagstones

Hello everyone. I am new in here.

Our back garden was overgrown with weeds growing between the flagstones. I used a pressure washer on them which worked and the back garden now looks fine. The problem is, these weeds will return.

How can I seal in between the flags? Could I use a weedkiller and then Kiln Sand as I've been told? Someone else suggested rock salt first to dry out & kill the weeds before using Kiln Sand.

If I do use Kiln Sand, will the pressure washer not blast it all away when the garden needs cleaning?

Hope you can advise.

Many thanks, Rob.


  • K67K67 Leicestershire Posts: 1,731
    Nothing stops the weeds returning so either pressure wash and resand, scrape the weeds out with a knife or use some form of weedkiller, 
    You could use mortar to fill the gaps but having tried this once I found any little gap or hole ended up with a weed and it was impossible to remove without damaging the rest of the mortar.
    There are fillers you can buy that arevsupposed to stop weeds taking hold but they are expensive but whether they work you would have to check the reviews.
    At least you have flagstones, deweeding a 5m x 17m drive made up of pavers was a 2 day job on my hands and knees after they banned the weedkiller that worked for 6 months , thankfully moved before I got too old to keep up with it.

  • Your reply is really appreciated. Many thanks.
  • KeenOnGreenKeenOnGreen Posts: 1,168
    @pleb.bcite   We have exactly the same problem, and they come up in hairline cracks.  We're not fans of weedkiller, but although we haven't tried it yet, I believe pouring boiling water over them would work.  

    We wouldn't normally do that near plants that we want to keep healthy, but for the situation you describe it would probably work.
  • K67K67 Leicestershire Posts: 1,731
    Sadly the boiling water doesn't work, for a start by the time you get it there it's not boiling!
    It will shrivel the top growth but not the roots, I have tried salt as well but that's not good for the insects living around.
    The only way if you are not a weedkiller fan is hand removal.
    Last year I grew an erigeron and that has self seeded inbetween in places and looks much nicer than weeds.
    You could try sweeping weekly with a stiff broom to dislodge newly grown weeds.
    I think the trick is not to let them grow too big before you get rid of them and certainly before they flower and set seed.
    Or if you have older children you could bribe them with extra pocket money to do it.
  • FlyDragonFlyDragon Greater ManchesterPosts: 653
    I just scrape them out/off with a patio brush with a metal scraper attached.  You only have to do it once every couple of weeks.  I have used pathclear weedol in the past which did kill everything except the marestail, but I'm trying to go chemical free, and actually I prefer the manual way as you don't have to wait for the weeds to grow enough to get rid, or put up with them looking ugly as they go brown and die. 
  • LoxleyLoxley Posts: 3,109
    I find weeding between paving cracks quite relaxing. (As long as they haven't got out of hand!) Take a cushion and a glass of wine ;)
  • Thanks for all your kind replies. What are your thoughts on using Kiln Sande in between the blocks?
  • K67K67 Leicestershire Posts: 1,731
    Kiln dried sand is what we use, cheap and easy to brush in as long as the area is dry.
    Depending on the width of your spaces you could use limestone dust, definitely need flagstones and gaps really dry and once you have got it in the gap you need to tamp it down hard, filling the gap up to the top.
    Once in make sure you sweep up excess well then go over with a very gentle spray of water, the limestone sets quite firm after a while but sadly not totally weed proof!

  • mikeymustardmikeymustard Posts: 239
    K67 said:

    ...Last year I grew an erigeron and that has self seeded inbetween in places and looks much nicer than weeds....

  • amberspyamberspy Posts: 370
    I actually done this a few weeks ago on mono block drive way 
    it’s only the bottom bit of drive gets lots weeds 
    I was fed up with it so I used path clear and left ten days then went back and got on hands and knees and scraped all them out then pressured washed it 
    it looks new again but unfortunately couple weeds have pop up again so just pulled these ones out 
    hear table salt helps but never tried that 
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