Zen Garden Life

Growing Parsnips in the Home Garden

By Zen Garden Life · Last reviewed November 8, 2026

Parsnip plants with feathery leaves growing in a wooden raised bed

Parsnips (Pastinaca sativa) are a slow, very cold-hardy root crop in the carrot family. They need a long season, about 100 to 130 days from sowing, and they taste best after the roots have been through several frosts, which turns some of their starch to sugar. The usual plan is to sow in spring and dig from late fall through winter, or the following early spring.

They grow much like carrots, only slower and larger, so most carrot advice applies.

Start with fresh seed

Parsnip seed loses viability quickly. Buy new seed every year: seed more than a year old often comes up poorly or not at all. Even fresh seed is slow, taking 2 to 3 weeks or more in cool soil, so sow generously.

When to sow

In most of the US, sow from early spring, as soon as the soil can be worked, through late spring. Later sowings are fine as long as the roots get about four months before the ground freezes. In mild-winter areas (roughly zone 8 and warmer), many gardeners sow in fall instead, so the roots grow through the cool months. The zone and frost date lookup gives your frost dates.

Soil

Parsnip roots grow 8 to 12 inches long or more, so loosen the soil at least 12 inches deep and remove stones and clods. Compacted soil, rocks and fresh manure all cause forked, stubby roots. Work in well-rotted compost, aim for a pH of about 6.0 to 7.0, and go easy on nitrogen. In heavy clay, a deep raised bed is the easiest fix.

Sowing and thinning

  • Sow 1/2 inch deep, several seeds per inch, in rows 18 to 24 inches apart.
  • Keep the soil surface moist until seedlings appear. A crust or a dry day can wipe out a sowing. A board or burlap over the row helps; remove it as soon as sprouts show.
  • Sowing a few radish seeds in the row marks where the slow parsnips are.
  • When seedlings are 1 to 2 inches tall, thin to 3 to 6 inches apart, depending on how big you want the roots. Snip extras with scissors.

Care

Water about 1 inch a week, more importantly during germination and early growth. Even moisture also prevents split roots. Weed carefully for the first couple of months; the seedlings are small and compete poorly. A mulch of straw or shredded leaves once plants are a few inches tall keeps the soil moist and the weeds down.

Watch out for the sap

Parsnip leaves and stems contain compounds (furanocoumarins) that make skin react to sunlight. Sap on your skin followed by sun can cause a red rash and blisters, sometimes leaving brown marks for months. Wear gloves and long sleeves when weeding, thinning or harvesting on sunny days, and wash off any sap.

Don't let garden parsnips go to seed and scatter. Wild parsnip, the roadside weed with the same effect on skin, is the same species gone feral.

Pests and diseases

  • Carrot rust fly: larvae tunnel into the roots. Floating row cover from sowing is the reliable control.
  • Parsnip canker: rough reddish-brown to black patches on the shoulders of the root, worse in wet soil and when roots are damaged. Rotate, avoid nicking roots, and choose resistant varieties such as 'Gladiator' or 'Javelin' if canker has been a problem.
  • Black swallowtail caterpillars eat the foliage but rarely enough to matter.
  • Leaf spots and powdery mildew appear late in the season and usually don't affect the roots.

Harvest

The roots reach full size in about 100 to 130 days, but wait for several hard frosts before digging. They are long and break easily, so loosen the soil alongside the row with a garden fork and lift rather than pull.

Parsnips can stay in the ground all winter. Cover the bed with a thick layer of straw before the ground freezes if you want to keep digging (more on straw mulch), or leave them and dig in early spring as soon as the soil thaws. Harvest spring roots before new leaves start to grow. Once the plant begins growing again, the root turns woody as it sends up a flower stalk.

Storage

Parsnips need cold, humid storage, not dry. In dry air they go limp and rubbery. Keep them in a plastic bag in the refrigerator for several weeks, or packed in damp sand in a root cellar near 32°F for several months.

Roast them with other root vegetables, add them to soups and stews, or mash them on their own.