i got link-a-bords last year as part of my veg patch in my gardent, and put them on gravel site (so no membrane), first time growing my own veg so maybe hadn't thought this through properly!! I put John Innes No2 in in both of the raised beds.I had great crops. One of the beds is deep and the other is shallow, so giving me a bit of flexibility on crops to grow. Grew parsnips in the deeper bed, they were lovely. As you know, raised beds lose their nutrients, so this year am digging in home made compost and manure to improve the soil. I'm going to try and grow sweet corn in the deep bed this year - this may not be the right thing to do - but the deep bed is in a relatively sunny spot, so thought I'd give it a go! will update the forum if i've got any harvest!