Why are My Parsnips Deformed and Misshapen?

Parsnips are a sweet, earthy, characteristic autumnal root vegetable. They’re also easy to grow and mostly problem-free. But root issues happen. Here, we’ll explore common causes of misshapen parsnips and how best to prevent them for a healthy, show-worthy harvest.

Written by Katherine Rowe Horticulture review by Sarah Jay Last updated: October 28, 2024 | 5 min read

A close-up of pale, elongated root vegetables freshly harvested, their skins lightly streaked with brown and twisted contours. The vegetables rest on a bed of hay, surrounded by faint green foliage and remnants of soil clinging to the roots.

Contents

Parsnips are hearty vegetables with a sweet, nutty flavor. Their crisp white roots resemble carrots and are just as versatile. Sometimes, root vegetables become misshapen as they develop. They twist, knot, fork, or stunt as they encounter growing problems. These aren’t what we want to see after waiting patiently for a parsnip harvest.

In the right cultural conditions, parsnips need little additional maintenance to prevent them from becoming deformed or misshapen. They’re primarily pest and disease-free, but sometimes problems arise and impact maturing roots. Here, we’ll explore why they might emerge deformed. While not showy or award-winning, the roots should be just as tasty and nutritious.

Growing Notes

A cluster of long, pale root vegetables pulled from the dark soil, lying among lush green leaves with a few yellowing edges. The surrounding earth is crumbly, with small patches of green shoots indicating nearby plant life. — Sow them in spring before the last frost for an autumn harvest.

Parsnips are compact root vegetables, but they’re long-maturing, developing in about 100 to 120 days. Sow them in spring before the last frost for an autumn harvest. In mild climates, sow them in late summer or fall for overwintering. The cold-season growers sweeten after a few freezes. Harvest in the fall after temperatures drop for the best flavor.

Optimal growing conditions for the easy-care producers include:

Full sun (six or more hours of sunlight daily)
Loose, sandy, fertile, well-draining soil
Acidic, neutral, or alkaline soils with a pH of around 5.8 to 7.5
Cool conditions in spring, fall, or winter (60-65°F or 16-18°C are ideal growing temperatures; they withstand cold better than heat)
Consistent moisture with about one inch of water per week (rainfall and irrigation)

Heavy Soils

A root vegetaible emerges from freshly tilled brown soil, its delicate leaves unfurling. The cracked earth around the plant shows signs of recent moisture, with clumps of dirt scattered across the patch, fostering new growth. — They like light, sandy loams to easily move through for even root development.

Parsnips adapt to various soil types but do best in organically rich, loose soils. They like light, sandy loams to easily move through for even root development.

Ensure soil and compost amendments are free of debris, clumps, and rocks. The roots change shape as they bump into impediments underground, so rockier soil can cause misshapen or deformed parsnips.

In dense or compacted soils, taproots struggle to create growing space and may become bent, twisted, or forked as they seek nutrients and water.

Work at least six inches of completely broken-down plant material (compost or leaf mold) into the composition to improve texture, aeration, moisture retention, drainage, and nutrition. Good drainage is essential to healthy development.

Fertilizer Issues

A hand gently sprinkles granules of fertilizer near vibrant green seedlings with bright red stalks and glossy leaves, nestled in rich brown soil. The young plants are surrounded by a meticulously prepared garden bed, where sunlight highlights the vivid colors. — In fertile soils, they thrive without additional applications.

These vegetables don’t need as much nitrogen as some crops. In fertile soils, they thrive without additional applications. They don’t rely on overly rich compositions and do well with incorporating completely cured organic material at planting.

A side-dress of 1-2-2 about six weeks after planting boosts healthy root development.

Too Much

A gardener wearing blue gloves carefully pours fertilizer around a healthy green plant with broad leaves, growing in rich dark soil. The surrounding area shows signs of other small plants with soft green leaves soaking up the nutrients. — Excessive nitrogen also increases susceptibility to pests and diseases that distort roots.

Overfertilizing increases nitrogen, which promotes quick, leafy growth. The fast production of leaves and stems means less energy and nutrients sent to developing taproots. The parsnips may become misshapen, deformed, or forked as the plants weaken under the excess.

Excessive nitrogen also increases susceptibility to pests and diseases that distort roots. A light hand is best when it comes to these rugged growers.

Too Little

A gloved hand scatters tiny seeds into a freshly prepared garden bed, the soil dark and soft with moisture. The carefully tilled earth is ready for planting, and small grains of seed are falling into the rows, signaling the start of new growth. — Remember to break up any clumps for even distribution, prevent fertilizer burn, and remove impediments.

If upper growth becomes yellow and stunted (and it’s not from watering issues), nutrient deficiency may be the cause. A side-dress of a low-grade balanced fertilizer or organic matter may help.

This occurs more in soils that lack available nutrients, like clay and sand. Apply a side dress – keeping the material away from leaves and stems – in late May or October. Remember to break up any clumps for even distribution, prevent fertilizer burn, and remove impediments.

Root-Knot Nematodes

A close-up of root nodules clinging to a thin plant stem, showcasing white, lumpy formations along the light brown surface. The background is a blurred green field, emphasizing the intricate structure of the roots and their connection to the plant. — The soil-dwelling pest infests roots, causing cankers and a knotted appearance.

Knotty, deformed parsnip roots and misshapen, small yields are signs of damage from root-knot nematodes. The microscopic roundworms are difficult to see with the naked eye, but their path of destruction is evident and the woe of carrot and parsnip gardeners.

The soil-dwelling pest infests roots, causing cankers and a knotted appearance. Upper growth may show stunting, pale leaves, wilting, and leaf drop. Underground, roots may turn brown and soft, develop galls or dark patches, or become gnarled.

Unable to absorb moisture and nutrients through the impacted roots, the plants decline. Root-knot nematodes travel through various means: raindrops and irrigation splashing, soils, newly added plantings, garden tools, shoes, and more. They overwinter in the soil and dropped debris.

Treatment

A long root, tangled and rough-textured, hangs in mid-air with dirt still clinging to its surface. The earthy brown root contrasts against the background of soft green foliage, indicating it has just been pulled from the ground. — The best action is to remove and discard infected material and surrounding surface soil.

It’s challenging to treat a nematode infestation. Adding beneficial nematodes to the area can help, as they prey on root-knot species. Mycorrihizael fungi, too, show some success at suppression.

The best action is to remove and discard infected material and surrounding surface soil. Keep these materials away from plantings and the compost pile to reduce harboring the nematodes.

In severe cases, remove the crop and solarize the soil with plastic sheeting to help eliminate the population. You can also apply treatments of beneficial nematodes in temperate weather ahead of your next growing season to eliminate root knot nematodes.

Prevention

Hands gently hold a scoop of dark, rich soil, preparing to place it into a freshly dug hole in the garden. A green seedling is nearby, surrounded by a carefully dug trench, with a small spade resting in the background ready for more planting. — Support beneficial bacteria, fungi, and predatory nematodes by amending with compost, leaf mold, or other organic matter.

Crop rotation is the best prevention against recurring infestations from root-knots that overwinter in the soil. By changing crops and planting sites, we reduce prime food sources and habitats. Avoid planting parsnips and carrots in the same area in successive years. Skip two or three seasons, planting them in different sites. Non-susceptible crops like corn and marigolds make good infill rotations to dissuade the lingering pests.

Promote and support beneficial bacteria, fungi, and predatory nematodes by amending with compost, leaf mold, or other organic matter. Keep the area weed-free to reduce competition and prevent the spread of pests and diseases.

Root-knot nematodes are less active in cool temperatures. Parsnips grow best in cool weather, and planting them when temperatures are in the low 60s°F (~16°C) helps avoid nematode active seasons.

Densely Planted

A gardener's hand pulls a large, knobby root vegetable from the soil, the leaves broad and bright green. The garden bed is lush with surrounding plants, and the dark soil shows signs of cultivation, with nearby crops thriving in the warm light. — Spacing is important for the best yield and flavor.

The vegetables grow well in garden beds, containers, vertical planters, and raised beds. Direct sowing their seeds is an easy way to promote even taproots. Sowing right in the ground avoids disrupting the developing roots at transplanting (potentially affecting the shape of future growth).

Spacing is important for the best yield and flavor. Start with a thick seeding, as germination can vary. As they sprout, thin seedlings four to six inches apart to allow for mature plants. 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. Avoiding overcrowding also reduces competition for water, nutrients, and sunlight. Fully developed roots form as a result of healthy growing conditions from the start.

Watering Fluctuations

A gardener waters a vibrant garden filled with leafy green plants, the large leaves standing tall as the water trickles down. The rich soil appears well-nourished, with various plants surrounding the main crops, indicating a healthy and thriving garden bed. — About one inch of water per week for evenly moist soils is usually sufficient.

Consistent moisture promotes the best vegetable development. About one inch of water per week for evenly moist soils is usually sufficient.

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. Changes between wet and dry conditions also contribute to splitting and cracking.

Overwatering causes hairy roots and forking. Mulch around the upper leafy growth to help maintain moisture and regulate temperature.

Hot Weather

A lush garden bed showcasing rows of leafy green plants with broad, vibrant leaves reaching outward. The well-organized rows are filled with rich green foliage, indicating robust growth in the fertile brown soil that extends across the garden. — The vegetables grow best in temperatures below 75ºF.

Hot weather affects seed germination, but it also slows growth and leads to deformed or misshapen parsnip roots in maturing specimens. The vegetables grow best in temperatures below 75°F (24°C). A summer or early fall heat wave may produce a more bitter, smaller root.

Why are My Parsnips Deformed and Misshapen?

Growing Notes

Heavy Soils