Best Crop To Grow As Mulch

Hello.

I am toying with the idea of putting one of my raised beds over to growing
crops purely for mulching the rest of the plot to improve soil quality long term and make me/the plot more self sufficent kind of along the lines of chop n drop permaculture. I already have some comfrey started from seed in trays..but i was wondering if anyone could give me ideas on what else i could grow here in the uk for this purpose.. Many Thanks.

pea and bean foliage make good additions to the compost heap and you can always take a crop off before you chop them.

You could try growing a very underated weed.  .  .   . . . . SEAWEED !     I'll get me coat.      Cheers,     Tony..

Just had a thought, If you've started comfrey from seed, then its the kind of comfrey that spreads like billy-o... you'll have a whole patch in no time. 
The other kind of comfrey is Bocking 14- its sterile and propagated by root division so it doesn't take over

And the OP said he was growing seeds.

Thanks for all responses

I`ve made my mind up and will be growing mulch crops in the bed earmarked. It gets some shade so the comfrey should love it there, ill let it just do its thing and then give it the barber shop treatment as and when its ready and import as much free organic matter as possible . I want to avoid buying to much compost (at the moment i might aswell ask for B&Q vouchers for Christmas). I think the idea of laying nettles on the soil is a good one i can see me and the kids having some very interesting trips to the local park with secateurs a large hessian sack and a tube of wasp- eze.
Along with the growing of the green manures for overwintering i should hopefully start seeing an improvement in the soil reasonably quickly..I did like the idea of growing sea weed Klefti but I`ve been down to the plot and it would appear that my polytunnel will only keep the water out.. ..bit of a shame really because i am partial to a bit of sushi.

As for the curry leaf Compost Queen i am waiting for the weather to warm up a bit and then im gonna try and get some going from cuttings from our local asian supermarket im not particulary optimistic but only time will tell..I've seen plants for sale online but they are quite pricey so ill have a go first..

Thanks for all your contributions its given me plenty of food for thought..

Helichrysum with curried prawns...mmm not sure you will be seeing that on masterchef any time soon...