The seed is hard to germinate and year after year mine failed
Then I found toilet roll innards.
half fill the cardboard tube with compost add one parsnip seed top up with compost.
place them together in a plastic tray and keep them watered so that the cardboard is always wet but not waterlogged
When the green shoots come through, gently peel off the tube, but you can leave it on because it will rot like a fibre pot and plant into a dibbled hole.
I suggest not too much fresh manure in the soil or they take on a shape of a monster from outer space.
A tip I read the other day is to sow 5 seeds in a group at he the intervals that you want your parsnips to grow, about 6 inches.
I have done the loo tube thing successfully with carrots.
http://www.allaboutliverpool.com/allaboutallotments_Vegetables_Beans_Runner.html
we have our parsnips in toilet rolls, only 3 failed, so we have 27 sitting in the coldframe now and will transfer them to the plot when they get a bit bigger :)