Vegetable · Apiaceae
Parsnip
Pastinaca sativa
Sow it, wait it out, and let a hard frost do the last little bit, and your parsnip turns sweet and nutty down in the soil.
Full sun
Every 5–7 days
36–75°F · 2–24°C
100–130 days
Overview
The parsnip is a cool-season root veg in the carrot family, and it's grown for that pale, tapering taproot it slowly builds up underground. It's technically a biennial, but most folks treat it like an annual, pulling the root its first autumn instead of waiting around for it to flower. Sweet, starchy, and a touch nutty, it's been feeding northern kitchens for ages.
Here's the deal though: patience is the price you pay. The seed's slow and doesn't keep long, the plant takes its sweet time, and the roots want 100 to 130 days before they're worth pulling. And what do you get for waiting? A veg that actually gets better with cold, since a hard frost flips its starch to sugar and makes the flavor richer.
Growing a good one really comes down to two things: the soil and the wait. Give it deep, loose, stone-free ground so it can run straight down, keep the bed moist while that slow seed wakes up, and hold off harvesting until the frosts show up. One thing to keep in mind: the leaves and sap can burn skin in the sun, so those tops are worth handling with a little care.
Care
The short version: parsnips want full sun and deep, loose, stone-free soil, about an inch of water a week to keep things steady, just light feeding, and a long wait through to a frost-sweetened autumn harvest.
Light
Parsnips really want full sun if you're after the biggest roots, though they'll cope with partial shade just fine. Less light just means a smaller harvest, so give them the sunniest spot you've got.
Water
Keep the soil evenly moist, roughly an inch of water a week. Bouncing between bone dry and soaked is what splits and cracks the roots, and that steady moisture matters most during the long wait before the seed's up, when a dry, crusted surface can stop things cold.
Soil
This is the one that really makes or breaks it. Parsnips need deep, loose, well-drained sandy loam cleared of stones and clods down to 12 to 18 inches, or the taproot forks instead of running straight. Shoot for a pH of 6.0 to 7.0.
Temperature
They're tough and happy across a wide range, roughly 36°F to 75°F (2°C to 24°C). The roots take frost in the ground no problem, and honestly that cold is exactly what sweetens them.
Humidity
Plain outdoor air suits them just fine, somewhere around 40% to 70%, so there's nothing to fiddle with here. It's the soil moisture that really counts.
Feeding
Go easy on the food. Feed once at sowing and again mid-season with a balanced, low-nitrogen fertilizer, because too much nitrogen or any fresh manure pushes forked, hairy roots instead of clean ones.
Pruning
Parsnips need pretty much no pruning. Thin the seedlings to 3 to 4 inches apart once the true leaves show up so the roots have room to fatten, and snip off any flower stalk that tries to bolt in the first year.
Size & spacing
The leafy tops stand about 12 to 18 inches (30 to 45 cm) tall and spread 8 to 12 inches (20 to 30 cm). Thin plants to 3 to 4 inches apart in the row so each root's got room to swell.
When to plant
Parsnips run on a pretty slow clock, so don't expect quick results. Direct sow in early spring, a few weeks before the last frost, once the soil's workable and at least 40°F (4°C), then let them do their thing all season. Hold off harvesting until late fall and into winter, because that hard frost is what makes 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 hiccups happen where you can't see them, either at sowing or down in the root. A bare row or a wonky root usually comes back to the seed, the soil, or the weather. Find the closest match below, then fix the cause so next season goes smoother.
Weeks gone by and still no seedlings
Wondering why nothing's come up? Nine times out of ten it's the seed, because parsnip seed doesn't keep, so anything left over from last year usually won't sprout. The seed also needs its 14 to 28 days with a bed that never dries out, since a crusted top stops it in its tracks. Grab a fresh packet each spring, keep the surface damp until you see green, and pop in a few fast radishes so you'll know where the row is.
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 come up whiskery
A parsnip wants a clear shot straight down, so stones, clods, and heavy soil are what send the taproot forking off in odd directions. Too much nitrogen or fresh manure does much the same thing, pushing whiskery, forked roots, and so does moving a plant that would rather stay put. Dig the bed deep and pick out the rocks before you sow, keep feeding low in nitrogen, and just sow where it'll grow.
Fix:
- Cultivate and de-stone soil deeply before sowing
- Use low-nitrogen, well-rotted amendments only
- Direct sow rather than transplant
Dark, sunken rot where the shoulders meet the soil
That dark, caved-in patch at the top of the root is canker, a fungal rot that likes wet, poorly drained ground and sneaks in through any crack or nick at the crown. A soggy year makes it worse, no surprise there. Sort out the drainage, hill a bit of soil over the exposed shoulders, and lean on tougher types like Gladiator or Cobham Improved Marrow that don't mind it much.
Fix:
- Improve drainage
- Hill soil over exposed shoulders
- Grow canker-tolerant cultivars such as 'Gladiator' or 'Cobham Improved Marrow'
Rusty little tunnels running through the roots
See rusty trails winding through the root? That's carrot rust fly larvae, which chew the lower root while the grown flies buzz around the leaves in spring and again in late summer. Throw a floating row cover over the bed to keep the flies out, move the patch off last year's carrots and parsnips, and wait out that first flight before you sow.
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's peeled and cooked, and a stray nibble won't hurt a pet. The catch is in the leaves and sap, which carry furanocoumarins that can burn skin in the sun, so handle the tops with gloves and don't let animals graze the leaves freely.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds
Safe for
People
Cats Mild
No need to stress about the root, since the ASPCA doesn't list parsnip as toxic to cats and a little nibble won't do a thing. It's the sap on the leaves that's the catch, because it can leave the mouth or thin-furred skin a bit sore, so it's worth keeping a cat away from the tops.
Dogs Mild
The cooked root's totally fine, and parsnip isn't on the ASPCA toxic list for dogs anyway. A dog that chews the leaves might get a sore mouth from the sap, though, and sap on bare skin can sting once the sun's on it, so keeping the foliage out of reach is the easy call.
Horses Mild
Horses can graze the tops without much drama, but here's the thing: the furanocoumarins in the leaves can leave pale, thin-skinned spots like the muzzle sore once the sun hits them. Give any bare skin a quick look for irritation or peeling after they've been in the patch.
Rabbits Mild
A bit of parsnip makes a nice treat for a rabbit, and the root won't hurt at all. Just go easy on the leafy tops, since the sap can irritate, and only hand over a small amount at a time.
Livestock Mild
Cattle, goats, and sheep can eat the foliage without trouble, but those same sun-triggered compounds might redden or blister pale, exposed skin around the face. So the bit to watch is heavy grazing of the green tops.
Birds Mild
Backyard hens will peck at parsnip root and scraps with no fuss at all. The leaves carry the irritant sap, though, so it's best not to toss fresh tops into the run.
People Root safe, sap a hazard
The peeled, cooked root is a sweet, wholesome veg that's completely safe to eat. The real catch is the sap on the leaves and stems, which holds furanocoumarins that set off phytophotodermatitis, a painful sun-driven rash with blisters and brown marks that hang around. Wear gloves and long sleeves when you're cutting or weeding the tops, and wash any sap off your skin before you head out 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 mostly differ in root shape, sweetness, and how well they shrug off canker. Here are the ones you're most likely to run into.
Hollow Crown
It's a long-rooted heirloom with broad shoulders and a sunken crown, and it'll only really pay off in deep, stone-free soil it can push straight down through.
Harris Model
It's a home-garden favorite, loved for smooth, even white roots that have a fine texture and turn out sweet every time.
Gladiator F1
It's a strong hybrid that laughs off canker better than most and still gives you smooth, even white roots.
Cobham Improved Marrow
It's a sweet, canker-tolerant one with clean-skinned, medium-length roots that get along in 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's only one way to get a parsnip going, and that's from seed sown right where it's meant to grow.
SeedModerate
Direct sow in early spring into workable soil · Germination takes 14-28 days; roots reach harvest size in about 100-130 days
There's really just one way to start a parsnip, and that's sowing the seed straight into the ground, because the taproot hates being moved. Grab a fresh packet every year, since the seed goes off quickly, and sow in early spring as soon as the soil's workable. Then it's a waiting game, because the seed can take 14 to 28 days to sprout, so keep the bed evenly moist the whole time, and you'll be pulling roots about 100 to 130 days later.
Myths
Parsnips are just white carrots.
Sure, they look like relatives, but parsnip and carrot are actually different species, Pastinaca sativa and Daucus carota. Parsnip's the sweeter, starchier one, and its flavor gets even richer once a frost has been through.
Parsnip leaves are safe to handle like any other garden green.
Not quite, because the leaves and sap carry furanocoumarins, and once they touch your skin and catch some sun they can bring on phytophotodermatitis, a blistering chemical burn. So handle the tops with gloves and covered skin, and keep any sap off bare arms.
Parsnips are inedible until they have been through a frost.
Nope, you can eat them whenever you like, frost or not. Cold just turns some of the starch into sugar, so a frosted root simply tastes sweeter rather than only then being okay to eat.