Last year summer 2010 we had the back garden (30 sq/m ) cleared, shrubs, trees, weeds etc all dug and cleared and levelled out, we was meant to get someone in to turf, however i decided to take the job on myself, but didnt have time ) now we are in March 2011, and the back garden is full of weeds every where, it does need some levelling, and i have considered buying a rotavator, however i have read that rather than rotavate, as this could make things worse, i should use a systemic weed killer, and kill all the weeds, wait a few weeks, and then rotavate and level out? Is this right?

Jason