Hollow Crown parsnips are an amazing parsnip. They have roots that taper down to 30-35 cm (12-14") in length and shoulders that reach 5-9 cm (3½") thick. You will have to work to get these out of the ground as they are so deeply rooted. The rewards are well worth the effort. Hollow Crown is an age old variety with smooth skin. Roots are white, fine grained and have a sweet buttery, slightly spicy, nutty flavor when cooked.
Parsnips are usually grown from seeds. Sow them 1cm (½”) deep and 7.5cm (3”) apart in rows spaced 30cm (12”) apart in well-drained soil that is rich in organic matter. Parsnips prefer full sun and a soil pH between 6.0 and 7.0. Keep the soil moist but not waterlogged during the growing season. Parsnips prefer consistent watering throughout the season. Fertilize with a balanced fertilizer every 4-6 weeks during the growing season.
Parsnips are ready for harvest once the roots are at least 2.5cm (1”) in diameter. They can be left in the ground until after the first frost to improve their flavor. To harvest, carefully lift the parsnips out of the soil using a fork or spade.