Vegetable · Apiaceae
Parsnip
Pastinaca sativa
Sow it, wait it out, and let a hard frost land the finishing touch, and the parsnip turns sweet and nutty deep underground.
Full sun
Every 5–7 days
36–75°F · 2–24°C
100–130 days
Overview
The parsnip is a cool-season root crop in the carrot family, grown for the pale, tapering taproot it drives down and fattens through a long season. It runs as a biennial, but gardeners grow it like an annual, pulling the root in its first autumn instead of letting it shoot up to flower the next year. Sweet, starchy, and gently nutty, it has powered northern kitchens for centuries and it rewards anyone willing to play the long game.
Patience is the ticket to the ride. The seed comes up slow and fades fast, the plant takes its time bulking up, and the roots want 100 to 130 days before they hit pulling size. And the payoff hits hard: this is a vegetable that gets better with cold, since a hard frost flips its starch to sugar and drives the flavor deeper.
Nail a great parsnip and it comes down to the soil and the wait. Hand it deep, loose, stone-free ground to plunge straight down through, keep the bed moist while the slow seed stirs, and hold the harvest until the frosts roll in. One heads-up rides along with the crop: the foliage and sap can burn skin in sunlight, so the tops call for a careful hand.
Care
The short version: give parsnips full sun and deep, loose, stone-free soil, about an inch of water a week to keep growth rolling, light feeding only, and a long, rewarding wait through to a frost-sweetened autumn harvest.
Light
Parsnips chase full sun for the biggest roots, though they will get by in partial shade. Less light just trims the harvest, so hand them the brightest patch you have.
Water
Keep the soil evenly moist, roughly an inch of water a week. Bouncing between bone dry and soaked splits and cracks the roots, and that steady moisture matters most during the long stretch before the seed breaks ground, when a dried, crusted surface can stall germination cold.
Soil
This is where the crop is won or lost. Parsnips demand deep, loose, well-drained sandy loam cleared of stones and clods to a depth of 12 to 18 inches, or the taproot forks instead of driving straight. Aim for a pH of 6.0 to 7.0.
Temperature
They are tough and roll across a wide range, roughly 36°F to 75°F (2°C to 24°C). The roots shrug off frost right in the ground, and that cold is exactly what sweetens them.
Humidity
Plain outdoor air suits them fine, somewhere around 40% to 70%, so there is nothing to fuss with here. It is the soil moisture that carries the day.
Feeding
Keep it light. Feed once at sowing and again mid-season with a balanced, low-nitrogen fertilizer, because too much nitrogen or any fresh manure drives forked, hairy roots instead of clean ones.
Pruning
Parsnips ask for next to no pruning. Thin the seedlings to 3 to 4 inches apart once the true leaves show so the roots can bulk up, and snap off any flower stalk that tries to bolt in the first year.
Size & spacing
The leafy tops shoot up about 12 to 18 inches (30 to 45 cm) tall and spread 8 to 12 inches (20 to 30 cm). Thin the plants to 3 to 4 inches apart in the row so each root has room to swell.
When to plant
Parsnips run on a slow clock, so lean into the long haul. Direct sow in early spring, a few weeks before the last frost, once the soil is workable and at least 40°F (4°C), then let them bulk up all season. Hold the harvest until late fall and through winter, since a hard frost is what turns the roots sweet.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Plant: Direct sow in early spring, 2-4 weeks before the last frost, once soil is workable and at least 4°C (40°F); parsnips do not transplant well due to the taproot.
- Harvest: Harvest roots in late fall and through winter; flavor sweetens markedly after one or more hard frosts converts starch to sugar.
Hardiness
USDA hardiness zones: 2–9
Temperature: down to -46°C
Troubleshooting
Most parsnip problems play out where you can't see them, either at sowing or down in the root. Track a blank row or a twisted root back to the seed, the soil, or the weather. Match the symptom below, then knock out the cause before next season.
Weeks of waiting and the row still stands empty
Chase down the seed first, because parsnip seed loses its spark fast and last year's leftovers are the usual reason a row never wakes up. Give the seed its 14 to 28 days under a bed that never dries out, since a crusted top will halt it flat. Crack open a fresh packet each spring, keep that surface damp until the green pushes through, and tuck in a few speedy radishes to flag the row while the crop gets going.
Fix:
- Sow fresh seed each season
- Keep the seedbed continuously moist until emergence
- Cover the row lightly to prevent crusting and interplant fast radishes to mark the row
Roots that fork, split, or turn whiskery
Clear the runway and the taproot dives straight, so stones, clods, and heavy soil are what knock it off course into forks and branches. Pile on nitrogen or fresh manure and the same whiskery, forked growth kicks off, and jostling the root by transplanting does it too. Dig the bed deep and haul out every rock before sowing, keep the feed low in nitrogen, and sow right where the crop will stand.
Fix:
- Cultivate and de-stone soil deeply before sowing
- Use low-nitrogen, well-rotted amendments only
- Direct sow rather than transplant
Dark, sunken rot biting into the root shoulders
That dark, caved-in patch at the top of the root is canker, a fungal rot that moves into wet, poorly drained ground and slips in through any crack or nick at the crown. A soggy season really fires it up. Sharpen the drainage, mound a little soil over the exposed shoulders, and reach for tough types like Gladiator or Cobham Improved Marrow that brush canker off.
Fix:
- Improve drainage
- Hill soil over exposed shoulders
- Grow canker-tolerant cultivars such as 'Gladiator' or 'Cobham Improved Marrow'
Rusty tunnels boring clean through the roots
Track those rust-colored trails straight to carrot rust fly larvae, which tunnel the lower root while the adults dart around the leaves in spring and again in late summer. Throw a floating row cover over the bed to shut the flies out, shift the planting off last year's carrots and parsnips, and hold your sowing until that first flight clears.
Fix:
- Cover rows with floating row cover
- Rotate away from previous carrot/parsnip beds
- Delay sowing to avoid peak fly flights
Toxicity
The parsnip you eat is a safe, wholesome root once it is peeled and cooked, and a stray nibble will not harm a pet. The catch lives in the foliage and sap, which carry furanocoumarins that can burn skin in sunlight, so handle the tops with gloves and keep animals from grazing the leaves freely.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds
Safe for
People
Cats Mild
Skip the worry over the root, since the ASPCA does not list parsnip as toxic to cats and a quick nibble means nothing. The sap on the leaves is the catch, capable of leaving the mouth or thin-furred skin a bit sore, so steer a cat clear of the tops.
Dogs Mild
The cooked root is a safe bite, and parsnip stays off the ASPCA toxic list for dogs. A dog that chews the leaves can pick up mouth irritation from the sap, and sap on bare skin can sting once the sun hits, so keep the foliage well out of reach.
Horses Mild
Horses crop the tops without much fuss, but the furanocoumarins in the leaves can leave pale, thin-skinned spots like the muzzle sore once the sun lands on them. Scan any bare skin for irritation or peeling after a stint in the patch.
Rabbits Mild
A little parsnip makes a great treat for a rabbit, and the root does zero harm. Ease up on the leafy tops, since the sap can irritate, and pass along only small amounts at a time.
Livestock Mild
Cattle, goats, and sheep munch parsnip foliage without trouble, though the same sun-triggered compounds can redden or blister pale, exposed skin around the face. Rein in heavy grazing of the green tops and the rest takes care of itself.
Birds Mild
Backyard hens peck at parsnip root and scraps with no bother at all. The foliage carries the irritant sap, so keep fresh tops out of the run.
People Root safe, sap a hazard
The peeled, cooked root is a sweet, wholesome vegetable that is completely safe to eat. The real hazard is the sap on the leaves and stems, which packs furanocoumarins that trigger phytophotodermatitis, a painful sunlight-driven rash with blisters and brown marks that linger. Pull on gloves and long sleeves when cutting or weeding the tops, and wash any sap off your skin before heading into the sun.
Wear gloves and long sleeves when cutting, weeding, or handling parsnip tops and sap, especially in sun; wash skin promptly if sap contacts it and keep that skin out of sunlight. The root is safe to eat once peeled and cooked.
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
United Kingdom
Animal PoisonLine: 01202 509000 (fee applies)
Australia
Animal Poisons Helpline: 1300 869 738
Varieties
Parsnip varieties split mainly on root shape, sweetness, and how hard they fight off canker. These are the ones you will run into most.
Hollow Crown
A long-rooted heirloom with broad shoulders and a sunken crown that pays off big only where the soil runs deep and stone-free enough to let it plunge straight down.
Harris Model
A home-garden star prized for smooth, uniform white roots that bring a fine texture and a reliably sweet flavor.
Gladiator F1
A powerhouse hybrid that beats back canker far better than most while still cranking out smooth, even white roots.
Cobham Improved Marrow
A sweet, canker-tolerant variety that turns out clean-skinned, medium-length roots ready to thrive across all sorts of gardens.
Companions
Parsnips do best near plants that mark their slow rows or keep the soil open, and worst beside relatives that share their pests.
Plant near
Radish: Fast-germinating radishes mark the slow parsnip rows and loosen the soil.
Bush beans: Legumes fix nitrogen and do not compete for the deep root zone.
Onion: Pungent alliums can help mask the crop from root-fly pests.
Keep apart
Carrot: Shares pests and diseases such as carrot rust fly, increasing pressure when grown together.
How to propagate
There is one way to launch a parsnip, and that is from seed sown right where it will grow.
SeedModerate
Direct sow in early spring into workable soil · Germination takes 14-28 days; roots reach harvest size in about 100-130 days
Kick off a parsnip one way only, by sowing seed straight into the ground, because the taproot flatly refuses to be moved. Grab a fresh packet every year, since the seed fades fast, and sow in early spring the second the soil turns workable. Then settle in, because the seed can take 14 to 28 days to break through, so keep the bed evenly moist the whole stretch, and you will be hauling up roots about 100 to 130 days on.
Myths
Parsnips are just white carrots.
They wear the family look, but parsnip and carrot are different species, Pastinaca sativa and Daucus carota. Parsnip runs sweeter and starchier, and its flavor deepens even further once a frost sweeps through.
Parsnip leaves are safe to handle like any other garden green.
The leaves and sap pack furanocoumarins, and the moment they meet skin and sunlight they can set off phytophotodermatitis, a blistering chemical burn. Work the tops with gloves and covered skin, and keep any sap off bare arms.
Parsnips are inedible until they have been through a frost.
Dig in any time, frost or not. Cold simply flips some of the starch into sugar, so a frosted root just tastes sweeter rather than only then turning edible.