Help ! What can i plant along side artichokes.

As some of you are aware i have just got my first allotment. It is covered in grass, so i hit it with round up and tried to rotivate it. The problem with that was the rotivater would not penetrate the grass!!

Ihave began to dig by hand, but the problem i have now is: where i was going to put my spuds and onions in i have found loads of artichokes. I have dug some out, but am i still ok to plant with these lurking underneath. I am worried they will push up onions and limit spud harvest.

Please help, i intended to plant today!!!!

haven't ever had them whisky. I will leave them in i think.
 Do you know how much distance i should leave between them and my new row of either spuds or onions? Probably spuds....

Thanks whisky  

JERUSALEM ARTICHOKE SOUP

25 g (1 oz) butter
1 onion, chopped
3 cloves garlic, crushed or chopped (preferably home-grown, home-smoked garlic!)
500 g (1 lb) Jerusalem artichokes, scrubbed and sliced
400 ml (3/4 pint) semi-skimmed milk
400ml (3/4 pint) home-made chicken stock
25g (1 oz) cornflour
Salt and freshly ground black pepper
2 dessert spoons fresh parsley, finely chopped
2 dessert spoons single cream

Melt the butter in a large heavy based saucepan and cook the onion with a pinch of salt until softened but not coloured. Add the garlic and artichokes and fry for a further few minutes. Then add the stock and milk, cover the saucepan and simmer gently for 25 minutes or until the jerusalem artichoke pieces are tender.

Process in a liquidiser or food processor until smooth then return to the rinsed pan. In a small dish, blend the cornflour with 2 x 15ml spoons water and stir in a few spoonfuls of soup, return this mixture to the saucepan and bring to the boil whilst stirring continuously. Remove from the heat, season to taste, stir in the parsley and garnish with cream.