Chemical-based treatment for moss and weeds

goldfinches

I bought a pint of distilled white vinegar today in M*rks and Sp*rks for 50p. I think, since all the lockdown cleaning articles started recommending it, that there is a somewhat genteel price war over said vinegar between Waitflower, Sainsby's and M*rks. 
Your lockdown diet sounds jolly nice to me, bottoms up!

Apodemus

White vinegar is 40p a pint (568 ml) in Tesco at the moment, with 5% acidity.  For comparison the Resolva spray is about 3.1% pelargonic acid, but pelargonic acid is a slightly stronger acid than acetic acid. Combining these two bits of information, you can expect about 50% more acidic effect from vinegar at the same volume of the two products.   That's good if you are using this to completely clear a path, but if you are using it to spot-kill a dandelion on a lawn, you might expect greater collateral damage to the lawn from overspray of the vinegar.    

twopenny

I already have my eye on the front block path that I use a wire brush on to use the chemical at prime growing time. Campanula and erigon abound.
Hope I've still got a path at the end of the treatment. 
On the other hand I wanted it a layer lower so.........

greyteam1959

twopenny said:

Thanks, cheap vinegar is 60p a half ltr. I know because I took to using it when white vinegar spray disappeared from the shops this year.

Online said it was too low in acid or something but I've used it for a year and does the same job.

I'll do a little experiment as I have to start again thanks to the rain and let you know. I need such things with this long lockdown like sitting and watching the grass grow

You ca buy white vinegar spray in Aldi

twopenny

Nearest Aldi a 60 mile round trip for me but could be useful for someone else. They do a spray in some shops here but it is twice the price of buying it in a bottle and putting it in a spray bottle - which is what I do.

I did check the lable of the Resolva weed killer and it is something unknown to me. Though I checked the multiple 'path weed killer' and one or two other types and a couple were indeed acetic acid so essentially vinegar.

Apodemus

2p, I guess we are playing fast and loose with the term "Resolva weedkiller"!  The Resolva brand includes products that have Glyphosate and/or diquat, products with Pelargonic Acid and products that claim Corn gluten meal as their active ingredient, so it's definitely best to check the label!  Actually, labels are pretty useless and it is best to click on the link to the Data Safety Sheet to see what is actually in the bottle. 

As with most of these products, you will see a host of other ingredients, such as isothiazole which is probably only there as a preservative for the weedkiller.  Some manufacturers also hide behind broad terms like "nonionic acids", which would cover both acetic acid and pelargonic acid, so you really don't know what you are buying. 

You may also see Silicon dioxide, aka sand, although Resolva further confuse matters by wrongly adding an 'e' to make this "Silicone dioxide", which is quite unlikely and not supported by the European Chemical Agency reference number that they cite.

Also worth noting that where the "active ingredient" is corn gluten meal, the jury is out on whether this has any useful effect whatsoever, beyond promoting growth by supplying nitrogen to the soil.