To ensure good germination, use fresh seed each year, sowing it directly into the ground after the soil has warmed in spring; in colder areas, warm up the soil before sowing by covering it with fleece or cloches.
Rake the soil to a fine crumb and create a trench ½ in (1 cm) deep across the bed. Sow clusters of three seeds at 6 in (15 cm) intervals along the row. Space rows 12 in (30 cm) apart. Cover the trench with soil, label, and water thoroughly.
Thin seedlings to one per station by pinching off or uprooting the weaker plants with your fingers. Cover with fleece where there is a risk of carrot fly damage. Weed regularly by hand, particularly while plants are young, being careful not to damage their developing roots. Watering is needed only during long spells of hot, dry weather.
Parsnip roots are ready to lift carefully with a fork as soon as the leaves start to die down; however, they are commonly left longer because exposure to frost improves their flavor. Mark the row so it is easy to find without the foliage. Parsnips can be left in the ground and harvested as required through winter.