Weedkiller for French limestone patio

[potato80]

Hi all

Anyone know an effective weedkiller that won't affect the finish of a limestone patio?

Have googled, but it's surprisingly difficult to identify a specific product that won't affect the finish

Thanks v much

 

[Mr Chibs]

Haven't tried on limestone, but have used white vinegar before for weeds. Might be worth trying a little patch.

 

[Odds]

Have a look at this list of the best weed killer for block paving and see what suits you, sir.
I usually use 'Roundup' as it's a proven product for weeds of all ages.

 

[StephenOak]

Have a look at this list of the best weed killer for block paving and see what suits you, sir.
I usually use 'Roundup' as it's a proven product for weeds of all ages.

Most of the things mentioned there have glyphosate as the active ingredient, which is no surprise as it one of a very few that are available for DIY use.

If you are going to use a glyphosate based weedkiller then all that matters is that the %age of glyphosate present is at the correct level, IIRC that is about 1% in solution. So buying a brand name, such as Roundup, is normally a waste of money.

NB, more is not necessarily better. Glyphosate is absorbed by the leaves and translocated to the roots, so using a stronger than optimum concentration will not have any more effect as the extra will just stay on the leaves.

Some glyphosate products (including one of those listed) are sold as a concentrate (normally with 360 in the name as 36% is the maximum available) and you dilute it. If you have a lot of area to do or you need to do it repeatedly then this will be more economical.

For paved areas then it is often useful to use something like Pathclear that contains glyphosate to kill the weeds and another ingredient that leaves a film on the surface to inhibit the germination of new weeds.

 

[Odds]

All i can say is what i see: weeds sprayed with RoundUp end their days swiftly.

 

[StephenOak]

And what happens to weeds sprayed with non-Roundup glyphosate?

 

[opps]

Salt?

Yeah it may damage the lawn though.

I must admit, that I didn't realise that the likes of roundup only work if absorbed by the leaves. In the past I have made the error of pulling the weeds out of our block paving and then sprayed them.

with thanks to @StephenOak

 

[JohnD]

Pathclear.

Do not pull up or hoe the weeds afterwards because this will break up the film that prevents remaining seeds germinating. You can cut them off, or re-treat a couple of weeks later when there is nothing more than tiny seedlings.