Parsnips may also be planted in double rows with 40 cm centres, with the two lines in the double rows at 6 cm apart and plants at 8 to 10 cm within the rows. If seeds are hand sown, thin seedlings three weeks after germination to 75 mm apart. Roots may be deformed if the plants are crowded. If the seed are sown with a vacuum or air seeder, this results in precise spacing and the plants are usually not thinned. At optimum temperatures, germination takes about 14 days, but in cold conditions it may take four weeks.
Establishment is better in the cooler months.
The seed is more difficult to germinate than carrots and requires regular moisture for establishment. Parsnips may be seeded with a nurse crop such as cereal rye, which germinates quicker than parsnips and protects the seedlings from wind and sand-blast. The cereal rye may be sprayed-off when the parsnips have three leaves. Fertilising The use of compost at up to 50 cubic metres per hectare to other crops in the rotation will be beneficial. It will supply organic manure, add nutrients and help to retain moisture in the soil.