How To Grow Parsnips From Seed
Parsnips, the nutty and sweet carrot relatives, are worth the wait from seed. While long to mature, the easy-care crops offer hearty, nutritious stock in cool-season cuisine. Gardening expert Katharine Rowe outlines how to grow parsnips from seed to enjoy their long history in cultivation.
Contents
Parsnips are a sweet, earthy root vegetable that become a staple of hearty autumnal cuisine. They also boast a long storage time over the winter. Easy to grow from seed and mostly problem-free, parsnips perform well in garden beds, pots, and raised beds.
While they’re long to develop (taking three to four months), parsnips take up relatively little growing space and don’t need a lot of tending as we await the harvest. They grow and sweeten with a nip of frost for a tasty fall and winter harvest. As root vegetables, they aerate soils as the long, tapered taproots form.
While late spring and early summer are best for sowing in cool climates, fall is prime for growing areas with mild winters. They’ll develop for a fall or late winter/early spring yield, respectively.
Follow these steps to successfully grow parsnips from seed.
All American Parsnip Seeds
- Matures quickly in as little as 95 days
- Sweet, tender roots ideal for roasting, mashing, or soups
- Long culinary history and versatile in gourmet cooking
- Sweetness improves when harvested after first frost
- Easy-to-grow and nutritious root vegetable
Javelin Parsnip Seeds
- 110-day growing period for full flavor
- Excellent canker resistance
- Sweet roots enhanced by cool temperatures
- Best harvested after the first frost
- Hearty, versatile root vegetable
Growing Parsnips From Seed
Parsnips, Pastinaca sativa, are ancient crops in the Apiaceae (carrot) family that appear as early as the Roman Empire. They have fibrous white taproots that reach up to one foot long. Both the roots and their leafy tops are edible, usually cooked as a savory addition.
Parsnips are compact root vegetables that develop in about 90 to 125 days, depending on the variety. They grow best in cool conditions when temperatures are in the 60 to 65°F (16-18°C) range, but are cold-hardy. Sow them in spring before the last frost for an autumn harvest (about 4 months before fall’s first anticipated frost).
In mild climates, grow parsnips from seed in late summer or fall for overwintering. The hearty roots sweeten after a few freezes as starches convert to sugars, so plan to harvest them after temperatures drop for the best flavor.
Parsnips are high in vitamins B, C, E, and K, as well as folate, potassium, and dietary fiber. Roast, mash, or cook them in stews or baked dishes for hearty, healthy goodness.
Parsnip seeds are tiny and papery. Plan to sow densely and choose a day that’s not windy for planting.
Location and Soil
Parsnips prefer a spot in full sun, with six or more hours of sunlight daily. They also tolerate partial shade, with four or more hours of sun. Organically rich, loose soils are best. Light, sandy loams provide even root development.
In dense soils like clay, taproots have to work to create growing space. They may become misshapen, bent, twisted, or forked as the roots seek nutrients and water.
At planting, amend lean or dense soil with compost, leaf mold, or other organic matter to increase aeration, drainage, nutrition, and moisture retention. Turn and loosen the soil to a foot deep for plenty of growing space. Remove rocks and clumps that will be impediments for the lengthy, fibrous parsnips.
Make sure the site is weed-free to reduce competition for seedlings and the developing roots. Weeds also harbor pests and pathogens that can cause growing problems.
Direct Sow
Direct sow parsnip seeds to promote even taproots. The roots are sensitive to transplant disturbance, and sowing in their permanent garden location avoids affecting the vegetable’s shape.
With the site prepped, grow parsnips from seed in spring, four to six weeks before the anticipated last frost date, or in fall in climates with mild winters. The best germination occurs when soil temperatures are near 60 to 70°F (16-21°C). Hot weather affects seed germination and also slows growth, leading to oddly shaped roots in maturing specimens. The vegetables grow best in temperatures below 75°F (24°C).
The slow and steady root vegetables can take up to three to four weeks to germinate, and may germinate sporadically over the course of those early weeks. Sow more than you need to ensure enough seedlings.
Sow parsnip seeds half an inch deep with a group of three seeds spaced three inches apart. If planting in rows, space them 18 inches apart to allow room for maturity.
Tend and Thin Seedlings
By sowing an overage of seeds, we can easily thin to promote the strongest seedlings. Proper spacing is essential in growing parsnips from seed for the best yield. When seedlings reach four inches tall, thin them so there’s one every three to four inches. Spacing too far promotes overly large roots, while cramped conditions can cause deformities.
Proper spacing means plenty of air circulation, making fungal diseases from damp and crowded leaves less likely. Less crowding also reduces competition for water, nutrients, and sunlight for fully developed roots.
Choose the most vigorous seedlings at the appropriate spacing to retain when thinning. Clip the excess seedlings at their base, rather than pulling them, to avoid root disruption of the remaining seedling.
Watering, Weeding, and Fertilizing
Consistent moisture promotes the best vegetable development and flavorful roots when you grow parsnips from seed. About one inch of water per week (rainfall and/or irrigation) for evenly moist soils is usually sufficient. Overwatering causes unattractive issues like hairy roots and forking.
Fluctuations in water cause stress, and growth slows as a means of conserving energy. Root disorders like stunting may occur, and flavor quality may decrease. Swings between wet and dry conditions also contribute to splitting and cracking.
Mulch around the upper leafy growth to maintain moisture and regulate soil temperature. A three-inch layer of weed-free straw or other material also helps suppress weeds. Keep weeds at bay as they spring up to avoid damage and disruption to the taproots. Lightly and shallowly cull weed seedlings to keep them from interfering with the forming parsnips.
As they grow, parsnip “shoulders” sometimes push up out of the soil. Hill or mound soil over the exposed tops to keep them from turning green due to sun exposure.
Parsnips don’t need as much nitrogen as some crops. In fertile soils, they thrive without additional applications. A side-dress of 1-2-2 about six weeks after planting boosts healthy root development. Keep the material away from leaves and stems.
Consider Companions
What can we grow with parsnips while they grow quietly underground for months? They make good partners for a number of crops, herbs, and flowering plants.
Radishes are an easy pairing and develop much more quickly than parsnips. Sow both in the same patch. The speedy radishes break through the upper crust, making way for parsnip seedlings to emerge. Harvesting the radishes loosens the surrounding soil so that the parsnip roots can continue developing.
Alliums like onions, chives, and garlic may help repel pests like aphids with their aromatic oils. Lettuce and peas are other mild-weather partners.
Avoid planting parsnips with other members of the Apiaceae family like carrots, parsley, fennel, celery, chervil, and anise. They’re susceptible to an easy transfer of pests and diseases. Keep the crops separate, and practice crop rotation. Avoid planting carrots and parsnips in the same spot in consecutive years.
