Try a F1 variety such as Gladiator and chit the seeds by placing some damp kitchen towel in a tray and place the seed (spaced out )on to it and keep moist, place on a warm window sill cover with some more cloth to exclude some of the light and it should start to germinate in 10 day or so, a white shoot will appear on the side of the seed, doing this saves a lot of time as parsnips can take a long time to germinate when sown direct, at least you will know your seed is viable, sow in March into prepared stations, i use a iron bar to do this, i push it into the soil and use a circular motion to make a tapered hole of about three foot or so and then put your compost mix in a week before you plan to sow to allow to settle and top up and firm in and sow three seeds or pre- chitted seeds and cover over, if you use the pre-chitted seeds just cut the kitchen towel and sow like that, be careful not to brake the shoot off as they are very brittle, sounds like yours did germinate but did not grow well, could be the growing conditions ie shade, ground to heavy or stoney to wet or to dry (it was a very warm spring plants needed a lot of water this year) , or even old seed (that is more lack of germination)or just not a very good variety there are so many variables in growing veg, just a few things to eliminate and work out what went wrong, good luck next year Chris