A parsnip picked in September and simply boiled is bound to be bland, mushy and unappetizing. But leave the roots in the ground until Christmas time or even the following spring, exposed to frost and near-freezing temperatures, and by some alchemy of cold on carbohydrates they become a different vegetable altogether—sweet, nutty and delicious. Parboiled and then oven-roasted until crisp-soft and caramelized, puréed alone or with potatoes, grated and fried in a version of potato pancakes or Swiss rosti, simmered slowly in a subtly spiced soup or hearty stew, parsnips (Pastinaca sativa) are as versatile as any vegetable and tastier than many. But you have to be patient.
Parsnip seed is slow to emerge and a 60 per cent germination rate is considered good. The young plants take their sweet time sizing up and need an entire growing season to mature. And then there’s the long fall or full winter wait until the roots’ starches change to sugars.
Where to plant parsnips
The best soil for parsnips is well drained and moderately fertile, and any texture from sandy to heavier clay loam will do. Crumbly compost is a suitable fertilizer, but steer clear of manure, which can cause hairy, misshapen roots. Dig or till the ground as deeply as possible—a full 30 centimetres is good—removing stones as you go (if root meets rock it will branch and fork). Then rake the surface to a fine, smooth finish.
While parsnip roots are hardy enough to survive winter, the seeds themselves are thin, papery and as fragile as they look, so anything a gardener can do to facilitate germination will result in a more even row. As with carrots and parsley—both parsnip cousins in the Apiaceae (formerly Umbelliferae) family—fresh seed is critical: those more than a year old will have lost all their vitality. Sometime during the week before or after the spring frost-free date, draw out a shallow furrow no more than 15 millimetres deep and plant seeds densely, at one per centimetre. If your soil is sandy, simply brush some over the seeded row and pat gently. In heavier soil, it’s prudent to cover the row with either sifted compost or sand, since crusted clay is hard for seedlings to break through. Keep the ground moist and look for sprouts in two to three weeks.