You need to cut down and remove the top growth, dig out the roots of anything like dandelion and then recover with the carpet. Leave until next spring then dig over and remove any visible roots.

Added to GoYpedia Weed Suppressing Membranes :o)

ty :)

It won't prevent those weeds from remaining alive beneath, I'm afraid - you will need to do as Moongrower suggests. The only way to kill of present weedgrowth and roots for good is to exclude all light, air and water - with thick black polythene anchored down tightly.

Yup Bamboo is right and even then the odd invasive weed will survive. Carpet can work as a mulch as long as it is wool and doesn't have a rubbery backing to it.

Haven't tried with carpet but heavy black agricultoral plastic (for wrapping haylege) took over six months, but did kill everything including thistles and rosebay wilowherb. (and couch grass!!)

yep, that's the kind of stuff I mean when I say heavy black polythene.

Carpet is banned on our local allotments, non porous polythene is best. As said before remove top growth and tap rooted plants, you could weed kill before putting the sheet down and anchor all over to prevent the sheet being blown away.

I did have local parents complaining to the allotment providers that my polythene was a danger to their children if they crawled underneath it - though they shouldn't be on the allotments anyway! However it was duly inspected and I heard no more about it. I suspect it was really the parents who didn't like to see it out of their back windows.

People need to get out more and learn to love what's around them instead of continuously complaining about what could happen to their little dears if they interfere in things that are none of their business! Whew! Need a cuppa now!

True - but don't take it to heart, it was a long time ago. enjoy your cuppa!