any advice on converting lawn to raised beds?

I didn't take the turf up first when I did mine I was far too eager to start growing stuff for that, and besides, I didn't own a spade, fork, hoe or any other gardening implements at the time! I think it's called sheet layering, the permaculture fan at the local lotty site recommended it, and I've had no problems with weeds coming through. We did have one very ambitious dandelion force it's way up, it was handily ready blanched because of the lack of light, so we pulled it up and ate it. Since then, nothing has made it through.

What I did was layer up a bed on the turf without digging it up at all:

First a layer of non-foam backed carpet, when our freecycle supply of this ran out we used cardboard that had been soaked in water. I can't remember why we had to soak the cardboard, though!

Then we put down the wooden beds themselves - ours are about a foot deep.
Into the bottom of them, we put some grass clippings and some well-rotted manure. I would be wary of using horse or cow manure at the moment because of aminopyralid - chicken manure might be a better option (check your yellow pages for poultry farms - our local free-range farm will not only supply it for free, they'll deliver it for free as well!) That was about 4 -5 inches deep.

Next we put in compost - couldn't use our homemade at the time because we had a bee's nest in the bin that we didn't want to disturb, so we bought some cheap from the local allotment site, who, I believe, got it really cheap from the council, so it may be worth approaching the council directly? We also mixed 50l vermiculite into the compost for each bed (hydroponics centres sell 100l bags for about £15, I have been told that you can pick it up cheaper as insulation from builders' yards, but I am wary of this because our local merchant couldn't guarantee the industrial grade was asbestos free :eek:). We also added worm castings that we got from the hydro centre - this was our biggest expense but the guy at the lotty site said either this or rock basalt to give our plants extra 'oomph', and this was the cheaper of the two. This layer went almost to the top of the beds.

Finally, at the top we mulched with straw, this protects the content of the beds and keeps moisture in. Then we planted through the straw and -voila - an effort-free raised bed! We are planning to add more worm casings and manure this year before we plant, but they have worked really well for us, we've had good crops and no weeds other than the odd seed weed that's probably been carried in by the wind or the birds.