Photo by Robert Couse-Baker.
Parsnips like to grow in full sun, but a bit shade is also okay. The soil needs to be around pH 6.5. Avoid adding nitrogen and use only well composted material, or else the parsnips will easily fork. They will also fork if there are stones in the soil, and they should be removed. The soil needs to be dug down to 30 cm (12 inch) since the roots go far down. I’ve had some trouble with wireworms, so remember to pick them up when digging if you convert your lawn into vegetable beds. It’s beneficial to grow garlic, onions, peas, potatoes and radish in the same bed as companion plants for parsnip.
Parsnip seeds don’t store well, so you need to use fresh seeds not older than a year. Sow in early spring in calm weather or else the seeds will easily blow away in the wind because they are light.
When the soil temperature is around 10 deg. C (50 deg. F) the seeds will germinate after 3 to 4 weeks in the ground. After the small plants have reached a height of 5 cm (2 inch) thin the rows so that the plants are 20 cm (8 inch) apart. Parsnips need 3 cm (1 inch) of water each week during the summer. Hand pick any caterpillars who decide to eat your crop.
Parsnip is often called a winter vegetable due to the fact that they are able to survive winter in the ground. If they are left outside when the frost arrives the starch inside them will turn into sugar and the taste improves. You can start harvesting parsnip in the middle of autumn or as late as January. Harvest before any new leaves start growing or the texture of the roots starts to degrade.
Cut off the leaves and throw them on the compost heap. Parsnips are best stored in dry sand in wooden boxes in a cool and dry place.