Posted: 28/01/2014 at 10:50
Keep in mind the fact that you are trying to grow the longest of a root crop.
By their nature they reach down deep into the soil to gain water and nutrients if you make life easy for them by fertilising and watering close to the surface they will not bother to take the journey and will simply stay where life is comfortable!
My own garden has been fed to the extreme in the past leaving the soil jammed with nutrients which at first sounds like heaven for a gardener but there is a downside if root crops are planted they don't bother to create tap roots!
One crop of parsnips I attempted to grow were huge with leaves waist high and three feet across!!...but when I dug them up the roots were a vast network of fine threads just below the surface like buried candyfloss!!!!
I hope this helps I wish you well let's know how you get on.