Posted: 02/10/2012 at 20:42
you don't mention the size of the plot- I wouldn't go for bleach or diesel. If it's that over grown, full of weeds and you want to completely start from scratch, same as previous advice I would go for the weed killer approach. If you are not fussy about what it kills, you can spray it all over- might take a couple of applications, it will work.
Can I just say there may be some really lovely plants lurking in there. I'm not a roses fan, I've dug out a few and given them away. If you go for the weedkiller approach or mini digger, there's a risk you might get rid of some hidden gems. Have you got a picture of the plot?