I have been offered a plot on the most beautiful site but the only plot available is completely covered with waist high brambles and weeds. I have a cunning plan - to strimmer it all down to a couple of inches - cover with a weed killer - the most inoffensive but effective I can find and then sheet it up for 3 months - build raised beds on it and fill with a mix of 'municiple' compost and whatever else I can get my hands on. wadayathink? will it work

No.

Because the most effective weedkiller, glyphosate (Roundup, Tumbleweed etc) has to be sprayed onto GREEN GROWING plants.

Strim = no green
Cover = no grow

striwm, wait for fresh growth, spray, wiat for death of weeds.

aaah - ok, cunning plan B required I think. Thanks for that Peter. I hadnt realised the weedkiller needed green growth. Had plans to get up there today and make a start but the snow has foiled me!

Peter is right Newbie. The most effective weedkiller is glyphosate based, and because it works by being taken up into the plant and carried around the system (hence 'systemic' weedkiller)to leaves AND roots, the more actively a plant is growing, the better the uptake, and consequently, the better the kill.

You will need to be patient and wait a few weeks for complete dieback. With the brambles and other big strong weeds you may need to be really really patient and apply two or even three times if you get any growback. But it is worth it, because it will be an end to perennial weeds. Hurrah!