Posted: 12/05/2014 at 18:20
KEF; excuse me if you already know this, but parsnip seed has a very short shelf life; that may be the cause of the germination problems.
Busy, you will still need some height around the bed. The carrot fly does not fly very high at all. I normally grow them in big high pots; one year I had to grow them quite low down in a very large grow bag, so I placed canes at each corner and tied polythene on to them to a height of 60 cm. It certainly worked.