How to Grow Parsnips

Overview

Parsnips are a classic winter root vegetable, prized for their sweet, nutty flavour that improves after a frost. They require a long growing season of around 4-5 months but are otherwise undemanding. Freshly dug parsnips from your own garden are incomparably better than shop-bought.

Health Benefits

Excellent source of fibre: Parsnips are rich in both soluble and insoluble fibre, supporting healthy digestion and helping you feel satisfied after meals.

Folate and Vitamin C: A good source of folate (important during pregnancy and for cell growth) and Vitamin C for immune support.

Potassium and manganese: These minerals support heart health, bone strength, and energy metabolism. Parsnips also contain a range of antioxidants, including falcarinol.

Soil Preparation

Parsnips need deep, stone-free soil to develop long, straight roots. Dig the soil to at least 40cm depth and remove all stones and debris. Avoid freshly manured soil, which causes forking. Aim for a slightly acidic to neutral pH of 6.0 to 6.8. Light, sandy soils produce the best roots.

Sowing & Planting

Always use fresh seed as parsnip seed viability drops sharply after one year. Sow directly outdoors from February to May in drills 1-2cm deep, spacing rows 30cm apart. Germination is notoriously slow and erratic, taking 2-4 weeks. Sow radish seeds alongside as a row marker. Thin seedlings to 15cm apart.

Care & Maintenance

Parsnips are largely trouble-free once established. Water during prolonged dry spells but they generally cope well without irrigation. Keep weeds down, especially while the seedlings are small and slow-growing. There is no need to feed parsnips if the soil was well prepared before sowing.

Harvesting

Leave parsnips in the ground until after the first frosts in October or November, as cold temperatures convert starch to sugar, improving the flavour. Lift as needed through winter using a fork. They can remain in the ground until February or March before they start to regrow.

Common Problems

Canker causes orange-brown rot at the crown of the root. Choose canker-resistant varieties and avoid damaging roots when hoeing.

Carrot fly also attacks parsnips, causing rusty tunnels in the roots. Cover with fine mesh or grow alongside strong-scented companion plants.

Poor germination is common with old seed. Always buy fresh seed each year and be patient with emergence.

Companion Planting

Parsnips benefit from being grown near peas and radishes, which help mark slow-germinating rows and fix nitrogen. Avoid planting near carrots and celery, which can attract shared pests.