How to Grow Parsnips
As an Amazon Associate we earn from qualifying purchases.
Learning how to grow parsnips is mostly a lesson in timing and patience. Parsnip seed is slow to sprout and does not keep well, so the first job is fresh seed sown early in loose, deep soil. The reward comes later, when cold weather turns the starch in the roots into sugar. University extension guides agree on the basics, even where their planting dates differ.
Parsnips are a long-season crop, so plan for several months from sowing to a usable root. The sections below cover soil, seed, spacing, care, harvest and storage, and each point names the extension page it comes from.
Quick answer
- Buy fresh seed each spring, because parsnip seed does not store well from one year to the next.
- Sow seed between one-quarter and three-quarters of an inch deep, as early as the soil can be worked, then thin seedlings to 2 to 4 inches apart.
- Keep the soil moist but not soggy, and keep weeds out while the plants are young.
- Dig the roots after the first light frosts, then store them cold, away from apples.
Start with a deep, loose bed
SDSU Extension says parsnips do best in full sun. It adds that they are not fussy about soil type, as long as the soil is not soggy or rocky, and that the soil should be worked to at least 18 to 24 inches. A raised bed can supply that depth. If you are not building one, the same page suggests planting where potatoes grew the previous year. PlantVillage describes the best soil as a “well-draining, loose, sandy soil which is free of large rocks and has a pH between 5.8 and 7.5.”
Both PlantVillage and Illinois Extension warn about fresh organic matter. PlantVillage says to avoid fresh manure because it can cause forked roots. Illinois Extension says fresh clumps of organic matter can cause misshapen or forked roots. PlantVillage also says it is beneficial to work some compost into the soil before planting. Work any compost in before you sow, rather than adding fresh material at planting time.
For a related root crop, see planting carrots in raised beds. For a wider list of crops that suit a raised bed, see vegetables to plant in raised beds.
Sow fresh seed early and mark the row
Illinois Extension gives early April or May as the planting window, in deep, fertile soil that is well prepared. Montana State takes a looser approach and says to plant “as soon as you can work the soil.” PlantVillage says parsnip is usually direct seeded and planted three to five weeks before the last frost date. Those windows differ by region, so check your local last frost date against them before you pick a day.
Fresh seed matters. SDSU Extension says, “Be sure to buy fresh seed each year, as the seed does not store well.” Illinois Extension adds that parsnip seed loses its ability to germinate after the first year, so unused seed should be discarded.
Depth is where the guides differ. SDSU Extension says one-quarter to one-half inch. Illinois Extension says 1/2 to 3/4 inch, Montana State says 1/2 inch, and PlantVillage gives 0.5 to 0.75 inch. Half an inch is the one depth inside all four ranges, so it is the choice that fits every guide.
Seed thickly. Illinois Extension advises that you “seed thickly, at least two or three seeds per inch to ensure a good stand,” and then thin later. Parsnip seed is slow to appear, so Illinois Extension suggests sowing a few radish seeds in the row. The radishes come up first, which marks the line and helps break the soil crust. SDSU Extension makes the same radish suggestion and notes that seeds can take two to three weeks to germinate.
Cool soil slows the start. SDSU Extension says the seed can germinate at 35 degrees Fahrenheit, but “it will germinate and grow much more quickly when the soil temperature is around 50 to 70 degrees Fahrenheit.” An early bed that warms in spring gives the seed an easier start.
Thin, weed and water steadily
Illinois Extension spaces rows 18 to 24 inches apart, or plants 8 to 10 inches apart in a bed. Once the seedlings are up, it says to pull the radishes and thin the parsnips to 2 to 4 inches apart. SDSU Extension gives 2 to 4 inches within a row, with rows 18 inches or more apart. Montana State gives 3 to 4 inches apart in rows 18 inches apart. The table below turns those spacings into a plant count for one 10-foot row.
| Final spacing in the row (inches) | Plants in 10 feet of row (120 inches divided by spacing) | Where the spacing comes from |
|---|---|---|
| 2 | 120 ÷ 2 = 60 | Low end of the SDSU Extension and Illinois Extension ranges |
| 3 | 120 ÷ 3 = 40 | Montana State, low end of its 3 to 4 inch range |
| 4 | 120 ÷ 4 = 30 | High end of the SDSU Extension and Illinois Extension ranges |
The counts are approximate, because they ignore the ends of the row. SDSU Extension says that ten feet of row should yield 5 to 7 pounds of parsnip roots. Divided across the plant counts above, that is about 0.08 to 0.12 pounds per plant at 2-inch spacing (5 ÷ 60 and 7 ÷ 60), and about 0.17 to 0.23 pounds per plant at 4-inch spacing (5 ÷ 30 and 7 ÷ 30). The division assumes every thinned plant reaches harvest, which the sources do not promise, so treat these as rough figures.
Keep the young plants weeded. Illinois Extension says to keep them “free of weeds by shallow hoeing or cultivation.” SDSU Extension suggests mulching lightly to hold soil moisture. Montana State asks for “1-2 inches per week” of water. Illinois Extension adds that during extended dry weather, the bed should get a thorough watering once a week, so that growth does not slow in summer. SDSU Extension wants the soil kept “moist but not soggy, to help form well-shaped roots.”
Feeding needs are modest. PlantVillage says to fertilize the plants five to six weeks after sowing. Illinois Extension says that if the plants look pale or stunted, a side-dressing of complete fertilizer in late June usually fixes the problem.
Wait for cold weather before you harvest
Parsnips improve in the cold. Illinois Extension says the flavor is not fully developed until the roots have been exposed to “near-freezing temperatures” for 2 to 4 weeks in the fall and early winter. PlantVillage gives the timing for harvest as well: “For best results, parsnips should not be harvested until after the first light frosts in Fall, when the tops of the plants have frozen.” It explains the reason: “Frost stimulates the conversion of starch in the roots to sugars giving the roots a sweeter flavor.”
Plan for a long season. Montana State says, “The root should be well-developed after being in the ground for around four months.” SDSU Extension lists 100 to 120 days to maturity. Counting back from your first hard frost in fall is a practical way to see whether the crop has enough time.
Some gardeners keep parsnips in the ground through winter. Montana State says, “Many gardeners leave parsnips in the ground over the winter and harvest in the spring.” Illinois Extension suggests a few inches of soil or straw mulch over the crowns after the first fall frosts. It also warns that “The roots lose flavor and become fibrous if you do not harvest them before new tops and seed stalks begin to grow.” SDSU Extension describes parsnips as biennial, which means that a root left in the ground can flower, set seed and become a weed.
Dig, clean and store the roots
Illinois Extension describes a typical harvested root as “usually 1 1/2 to 2 inches in diameter and 8 to 12 inches long,” and says to dig it with a shovel, tilling spade or spading fork. SDSU Extension suggests cutting the tops off before you start digging. It also warns, “Be careful, as the roots bruise easily.”
Storage is where the guides disagree. PlantVillage says to twist off the tops, wash the roots, and refrigerate them in airtight bags. Illinois Extension says to remove the soil and greens gently, then store parsnips unwashed in a perforated plastic bag. This guide shows both methods rather than picking one, because the sources do not settle the question.
Two more storage notes are worth keeping. SDSU Extension says, “Store in the refrigerator away from ethylene-producing fruits, such as apples, which can cause the parsnips to become bitter.” Illinois Extension says that smaller parsnips “may be more flavorful and tender.”
Handle the plant with care
Gloves and long sleeves are the main advice. SDSU Extension says, “When working with the plant, wear gloves and long sleeves, and make sure to wash your skin if it comes into contact with the green parts of the plant.” It also says that the stems, flowers, leaves and seeds, every part except the roots, contain a chemical that can cause dermatitis, and that it “can also cause the skin to become very light sensitive.”
Illinois Extension says that “Some people have reported minor skin reactions when coming in contact with the plant vegetation.” It also notes that wild parsnip, which is the wild form of the same plant, has sap that can cause severe skin reactions when it is exposed to sunlight.
The sources also disagree about eating the leaves. PlantVillage says the leaves can be cooked and eaten as a vegetable. SDSU Extension says, “Only the tap root is edible.” Insects and disease are less of a worry. Illinois Extension says that “Parsnips are relatively free of both insects and diseases,” and that handpicking swallowtail caterpillars usually gives adequate control. SDSU Extension suggests fabric row covers if leafhoppers or parsnip maggots become a problem.
Common mistakes to avoid
- Sowing old seed. Illinois Extension says seed loses its ability to germinate after the first year, so unused seed should be thrown out.
- Adding fresh manure or clumps of organic matter at planting time. PlantVillage and Illinois Extension both link this to forked or misshapen roots.
- Harvesting before the first light frosts. PlantVillage says the roots should wait until after those frosts have frozen the tops.
- Leaving roots in the ground until spring growth starts. Illinois Extension says the flavor and texture drop once new tops and seed stalks begin to grow.
- Working around the plant with bare arms. SDSU Extension recommends gloves and long sleeves.
Frequently asked questions
Why are parsnip seeds so slow to come up?
Illinois Extension says parsnip seeds germinate very slowly, even under the best conditions. Sowing a few radish seeds with them marks the row, so you can cultivate before the parsnips appear. SDSU Extension adds that germination is quicker once the soil reaches around 50 to 70 degrees Fahrenheit.
How deep should parsnip seed be sown?
Plant it at about half an inch deep. That is the one depth that falls inside every range the guides give. SDSU Extension gives one-quarter to one-half inch, Illinois Extension gives 1/2 to 3/4 inch, Montana State gives 1/2 inch, and PlantVillage gives 0.5 to 0.75 inch.
Can parsnips stay in the ground over winter?
Yes, and many gardeners do it. Montana State says many gardeners leave parsnips in the ground over winter and harvest them in spring. Illinois Extension suggests a few inches of soil or straw mulch over the crowns after the first fall frosts, and it warns that roots lose flavor if they are not dug before new growth starts.
Why are parsnips forked or misshapen?
The sources name one common cause: fresh organic matter at planting time. PlantVillage says to avoid fresh manure because it can cause forked roots, and Illinois Extension says fresh clumps of organic matter can cause misshapen or forked roots. Work compost in before sowing, and keep fresh material out of the row.
Are parsnip leaves safe to eat?
The sources disagree. PlantVillage counts the leaves as edible once cooked. SDSU Extension says only the tap root is edible, and that other parts of the plant can cause dermatitis. If you want to try the leaves, check a second extension source first, and wear gloves while you handle them.
How we chose
We opened four parsnip pages from university and extension sites on 2026-10-23: Illinois Extension, SDSU Extension, MSU Extension in Montana, and PlantVillage at Penn State. We kept a claim only when one of these pages states it in plain words. Where two pages gave different figures for depth, storage or the leaves, we show both. Our own arithmetic is limited to the row count and the yield division, and each input is named in the text. One Michigan State parsnip page returned a blocked response when opened, so it is not counted anywhere in this guide.
What we could not verify
The pages we opened leave several questions open. The list below covers the gaps that matter for planning.
What the sources do not say
- None of the four pages gives a storage temperature for parsnip roots. Each one points to cold storage, but none gives a number.
- The pages do not agree on washing roots before storage, and that disagreement is shown above.
- No page gives a variety list, so this guide cannot say which parsnip types suit a particular region.
- SDSU Extension gives a yield for ten feet of row only. The pages say nothing about yield for a larger bed.
- The sources disagree on whether the leaves are edible, and this guide does not settle that question.
Montana State notes that many parts of Montana may not have a long enough growing season to grow a decent parsnip. The pages we opened do not say what to do in that case, so check with a local extension office for timing in your area. PlantVillage also lists disease and insect problems with management options. This guide leaves out those options and recommends none of them.
Bottom line
Sow fresh seed early at about half an inch deep, thin the row to 2 to 4 inches, keep it weeded and evenly moist, and dig the roots after the first light frosts.
Sources
- https://extension.illinois.edu/gardening/parsnip (opened 2026-10-23)
- https://extension.sdstate.edu/parsnips-how-grow-it (opened 2026-10-23)
- https://www.montana.edu/extension/nutrition/nutrition-cooking-culture/documents/ParsnipFFS.pdf (opened 2026-10-23)
- https://plantvillage.psu.edu/topics/parsnip/infos (opened 2026-10-23)
