Parsnips as compared to carrots takes longer. Parsnips seeds should be planted 1/2 inch deep and 1 inch apart in rows. Parsnips loves moist soil so make sure that the soil is moist. You can keep the moisture in the soil by applying mulch.
Parsnips can be harvested at the end of the growing season. Usually it takes around 16 weeks for parsnips to reach maturity. The frost gives a sweet flavor to parsnips. When leaving them in ground for winter make sure to cover them up with mulch.