Can I put weedkiller down in advance?

[SniffingOne]

Moved into a house last summer that has tegula block paving which is a nightmare for weeds. Is there a product I can put down in the cracks now ish that will stop them even starting to grow? Once they start it's impossible to keep on top of pulling them and I have small DC so don't want to be constantly using weedkiller when they're playing out.

I use salt. As in kitchen salt.
Here in Australia they are all crazy about roundup weedkiller and my neighbours use them by the bucket because no weedkiller is forever and weeds will find a way out.
I buy cheap kitchen salt and when there is a forecast of nice weather for several days I lay the salt in the cracks and leave it. Sometimes on resistant spots, I add white vinegar to the salt.

IT needs to be repeated.
If you don't want to use salt, boiling water straight from kettle is an option too depending on size of paving

I have block paving and I have had success using a mix of vinegar and salt - very strong solution mixed up and sprayed liberally along the cracks. It makes the environment completely hostile to plants without any danger to the dc.

I'd never have thought of salt and vinegar, I will give that a try!

Here in Australia they are all crazy about roundup weedkiller and my neighbours use them by the bucket because no weedkiller is forever and weeds will find a way out. Roundup is a bad idea in this situation. It will kill the already growing weeds but won't persist in the soil, so has no effect on future weeds.

In this situation you need something with a residual affect and a name like "pathclear", but I'm not sure any are available to amateur gardeners any more. So salt seems the way to go.

@MereDintofPandiculation I hate roundup and think my neighbours are crazy and I don't even need to see them doing it, I can smell it from my garden. So toxic. They all have children.

With salt, you need to be generous and it is not just a sprinkle like you would do on chips, but really leave a thick white line. At least, on the Australian crazy weeds I discovered here

A vote for https://www.lovethegarden.com/uk-en/product/weedol-ps-pathclear-weedkiller-1-litre

Care needed round the edges to make sure you don't kill anything you would like to keep.

No! That product has the same ingredients as the infamous roundup, probably carcinogenic to humans . Do not use glyphosate. IT is banned in Italy, Austria, Holland ....

Neither of the ingredients in Finallyclear's link are persistent. It looks as if there are no longer any persistent weed killers approved for amateur use. That's probably why there's so much attention given to salt and vinegar.

The problem with salt in the UK is that it'd be washed off the paving into the beds alongside.

Be careful overdoing the salt. Of it washes off into planting beds it's likely to kill the plants in there.

Blowtorching the weeds is an alternative method for block paving and relatively eco friendly as no chemicals.

It's quite a big area so I can't imagine blow torching it. How often do you have to salt? Realistically it will be a full day job so hopefully not often.

@SniffingOne

It's quite a big area so I can't imagine blow torching it. How often do you have to salt? Realistically it will be a full day job so hopefully not often.

We do this, it doesn't take long and it's very satisfying

Salt is a terrible idea if it’s likely to wash off into your garden beds.

Cormoran Every been out Bourke way?
They literally have random kms of dead orchards from salt die off caused by over irrigation, raising of the water table which raises the salt levels in the soil with it.

Blow torching doesn’t take that long.