The parsnip, like the carrot is a member of the parsley family and is a slow growing hardy, deeply rooted plant grown for its delicious long tuberous taproot. They are a good source of vitamin C, are rich in the B complex vitamins, folic acid and fibre.
Growth habits and planting needs
Parsnips prefer an open sunny site.
Due to the slow germination time for the seedlings it is important that the soil be friable, well drained, deep, rich and open to allow the seed to germinate and then for the extensive taproot and root sytem to establish well. The soil should not crust over and prevent proper germination.
Prepare the bed well a few weeks before planting by digging the soil to a good tilth, removing clods to a depth of 60 cm.
Parsnips prefer a slightly acidic ro neutral soil with a pH of 6.0 to 6.8.
They should follow fruiting plants in the crop rotation system because they require potassium but do not need much nitrogen so fertiliser is not needed.
Parsnip seeds need to be sown directly in the garden and the seed must be fresh to be viable so check the plant by date when you buy your seeds. Germination is often erratic due to storage conditions, so place your seeds in the fridge when you bring themhome to keep them at their best. The most viable seeds will be those harvested at the end of its two year cycle.
Wait until the soil is 10-12º C before planting the seeds and a day before sowing the seeds soak the bed well.
Plant the seeds to a depth of 1.5 cm spacing them 3-5 cm apart in rows 45cm apart. Due to long time time to germination it is vital to keep the soil moist around the seeds as they swell. Using a drip irrigation system that delivers water morning and evening helps keep the seeds moist as it is vital the soil does not dry out. Mulch well between the rows to stop evaporation and weeds and place a light sprinkling over the planted seeds so that the soil does not crust over.
The seeds will emerge in 21-28 days. When the plant has its true leaves thin to 12 cm apart by clipping the weaker seedlings with scissors. This will prevent root competition as the plants grow.
At two months, when the top of the plant has reached a height of 12 cm with 4 leaves spreading to 10 cm the taproot may have grown to a depth of 45 cm
Over the growing season water well during hot periods keeping the bed well mulched. The image below gives some idea of the mature growth and the need to give adequate space to the plant.
Planted in early spring the plants will be ready to harvest the next autumn or winter.
Parsnips are very slow growing and will be ready to harvest at about 18 weeks or 100-130 weeks from sowing. In Sydney that will be from around March and troughout autumn and winter. If left in the ground during the frosts of winter the starches in the parsnips are converted to sugars and develop an intense sweet and nutty taste.
The leaves will start to die down and they can be picked as needed once the root is about 20 -25 cm long and the top is 3-5 cm in diameter.
Loosen the soil around the parsnips carefully with a fork and lift them out. Turn the leaves that are cut off under or put in the composter.
Clip off the leaves and stems to 5 cm, wash of the soil and dry them well.
To harvest the best quality seeds for next season select two plants to cross pollinate and to leave to go to seed. Choose on of the best specimins to seed save and ensure a quality crop next season. The plant will re-shoot in the spring of the second year and grow a flower stem swhere the papery seeds develop for seed saving on flower heads of small yellow flowers.
When the seed heads are dry place a paper bag or old pillow case over the heads, tie off and cut the stemsfrom the ground. Hang upside down in a cool, dry airy place to fully dry. Then collect the seeds by shaking the seed heads in the pillow case or an old sheet and collect and store in an envelope in a tightly sealed glass jar kept in the fridge or cool place till needed next season.
Store parsnips in the refrigerator. Parsnips can also be cut into pieces and frozen for use in soups and stews and the freezing will improve their flavour and texture.
The parsnip can be baked, put into stews and soups, fried, mashed and in salads and coleslaw shredded thinly and sliced.