Parsnip

About Parsnip

Parsnips are a pale, carrot-like root with a nutty sweetness. They take the whole season to grow, and cold weather makes them much sweeter, so many gardeners leave them in the ground into winter.

Grown as an annual root crop; roots can stay in the ground over winter under soil or straw mulch and be dug in early spring.

When to plant

Timing is counted from your average last spring frost (and first fall frost). Sow & Tell works out the actual dates for your ZIP code.

• Sow seeds outdoors: from 2 weeks before to 2 weeks after the last frost

Sow seed thickly, since it is slow to sprout and can take up to 3 weeks. Parsnips grow all season; dig them after 2 to 4 weeks of near-freezing fall weather rather than counting days.

Soil

Deep, loose, sandy or loamy soil free of rocks; heavy clay or fresh clumps of organic matter cause forked, misshapen roots.

Have the soil tested and keep pH about 6 to 7 in loose, sandy loam; work in well-rotted compost or manure in spring or fall, not fresh clumps.

Feeding

• midseason (late June), only if plants look pale or stunted: complete fertilizer such as 10-10-10. Side-dress lightly beside the row and water it in; skip this if the soil was fertilized well before planting.

Too much nitrogen gives leaves instead of roots, and fresh manure or clumps of organic matter cause forked roots.

Harvest

Dig roots in late fall after several weeks of near-freezing weather, or leave them mulched and dig in early spring before new growth starts. Roots that start to send up a flower stalk lose quality.

Dig roots once, in late fall or early spring; cold weather makes them sweeter. Dig overwintered roots before they start a flower stalk, when quality drops.

Varieties (8)

Extension sources name only a handful of parsnip varieties and give little detail about most of them. Parsnips take about 100 to 120 days (Wisconsin Extension planting guide).

Pests to watch for

Carrot weevil, Mice (house mice and deer mice)

Diseases and problems

Powdery mildew, Common scab

In the kitchen

Roasted, mashed, pureed into soups or added to stews; the roots can also be eaten raw.

Keeping it: Refrigerate unwashed roots in a perforated bag for 2 to 3 weeks. Or leave them mulched in the garden and dig as needed; frost makes them sweeter.

Safety: The leaves, stems and sap contain furanocoumarins that can make skin burn and blister in sunlight. Wear gloves, long sleeves and long pants when working among the foliage, especially on sunny days (NC State, UMN).

Pets: Not listed as toxic by the ASPCA (its 'Cow parsnip' and 'Poison parsnip' entries are different, wild plants).