How to Grow Parsnips

Parsnips (Pastinaca sativa) are a cool-season root vegetable that thrives in cooler climates or during cooler parts of the year in warmer regions. Here’s how to grow parsnips successfully.

Article Index:

• Best Time to Plant Parsnips
• Ideal Soil Conditions for Growing Parsnips
• Parsnip Planting Tips and Companion Plants
• Care During the Growing Season
• Common Parsnip Pests and Diseases
• Harvesting & Storage

Best Time to Plant Parsnips

Parsnips prefer a long growing season with cool weather and typically mature in 100-130 days. In cooler climates direct sow parsnips in early spring as soon as the soil can be worked through early summer. These will be harvested in the spring. In warmer climate areas, plant in the fall for a spring crop. 

In the low desert of Arizona, plant parsnips from mid-September through November.

The ideal temperature for growing parsnips ranges from 50°F to 70°F (10°C to 21°C). They need a touch of frost to develop their sweet flavor, making them a perfect late-fall or winter crop. Parsnips are frost-hardy and can withstand cold temperatures down to 20°F (-6°C).

Ideal Soil Conditions for Growing Parsnips

Parsnips prefer deep, well-drained, loose soil with a neutral pH (6.0-7.0). Avoid heavy clay or compacted soils, as they can cause misshapen roots. Ensure the soil is loose to at least 12 inches (30 cm) deep for healthy root development. Read more about soil in this guide.

Amending with compost or organic matter helps increase fertility and drainage. Avoid using fresh manure, as it can cause the roots to fork and become distorted. Use well-composted organic material instead. While parsnips are not heavy feeders, they benefit from compost and worm castings added to the soil at the beginning of the season. Avoid high-nitrogen fertilizers, as they can lead to leafy growth at the expense of root development.

Parsnip Planting Tips and Companion Plants

Direct sow parsnip seeds as they do not transplant well due to their long taproots. Sow seeds ½ inch (1.25 cm) deep, spaced 3-4 inches (7-10 cm) apart in rows 12-18 inches (30-45 cm) apart. Thin seedlings to 6 inches (15 cm) apart to give the roots ample room to grow. For square-foot gardening, plant 5 -9 per square.

Use fresh seeds each year, as they lose viability quickly. Parsnip seeds can take 2-4 weeks to germinate, and their germination rate may be low. Keep the soil consistently moist during germination. Last season, I planted parsnips next to turnips at the same time. The turnips were several inches tall when the parsnips finally germinated. Be patient! 

Onions, garlic, and peas are good companion plants for parsnips. This guide explains companion planting in more detail.

Care During the Growing Season

Water parsnips regularly, keeping the soil moist but not soggy. Aim for about 1 inch (2.5 cm) of water per week and mulch around the plants to retain moisture and suppress weeds.

Hand-weed around the plants to avoid disturbing the shallow roots.

Watch for pests like carrot root flies, aphids, and nematodes. Floating row covers can help protect the plants, especially during the seedling stage. Parsnips can also be susceptible to fungal diseases like root rot and leaf blight. To reduce the risk, ensure proper drainage and avoid overcrowding, which improves air circulation.

Harvesting & Storage

Parsnips are ready for harvest after 100-130 days when the roots are about 8-12 inches (20-30 cm) long. Frost improves their flavor by converting starches into sugars. Cold weather and frost significantly improve their sweetness, making them even tastier.

To see if they are ready to harvest, dig around the top of the root to see how thick they are getting, or harvest one to check for size. In hot summer climates, when it begins to warm up in spring, it’s time to harvest your parsnips, no matter their size. In milder climates, parsnips can be left in the ground through winter and harvested as needed. Loosen the soil with a garden fork before pulling them out to avoid breaking the roots. 

Freshly harvested parsnips can be stored in a perforated plastic bag in the refrigerator for several weeks. For long-term storage, keep parsnips in a cool, damp place like a root cellar or bury them in sand to preserve them for several months.

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