A staple of the Sunday roast and a favourite in warming soups, the parsnip (Pastinaca sativa) is a root vegetable well suited to growing in our cool climate. While best known as a winter harvest, spring is the ideal time to get sowing parsnip seed in your garden as it needs a long growing period.
Although parsnips are in the ground for a long growing period, they need hardly any looking after once they have established, and are ready to harvest in late autumn. Parsnips will reward your patience with a sweet, earthy flavour and a harvest that will see you through the colder months. Thanks to their hardiness, they can be left in the ground over winter, making them a brilliant low-maintenance crop.
Parsnips are grown from seed, but the secret to success is always to use fresh seeds. Parsnip seeds lose viability quickly, so a new packet each year ensures better germination. To speed things up, many gardeners soak them overnight before planting.
Choose a sunny spot with deep, well-draining soil. Avoid adding manure as, like their carrot cousins, rich soil can cause parsnips to fork but they do well as a follow-on crop from brassicas.
Parsnips grow best in a relatively stone free soil and seeds can be sown directly where they are to grow. Sow seeds in finely raked soil from April onwards when the soil has warmed to at least 13°C (55°F) to ensure better germination rates.
Sow seed in threes 1cm (1/2in) deep, at a spacing of 15cm (6in) apart, with rows 30cm (12in) apart. Cover with a fine layer of soil and water using a fine rose attachment on your watering can so as not to flush the seeds out of position.
Parsnips can take up to 28 days to germinate, so be patient. Once seedlings reach 15cm (6in) tall, thin them to 8cm (3in) apart by lifting the two weaker seedlings to use in a salad.
If you are short on space, you can grow shorter-rooted parsnip varieties in deep containers like an old dustbin with drainage holes which works well - just make sure they have plenty of depth to grow straight down.
Or consider using the space around sown parsnips to grow quicker-growing crops like radish or lettuce which can be harvested before the parsnips need to fill the space.
Parsnips thrive in cool weather but struggle in extreme summer heat, which can make them taste bitter, so remember to water if the weather turns very dry. Irregular watering can cause the roots to split. A mulch of grass clippings, straw, or compost helps regulate soil temperature, lock in moisture, and keep roots happy.
Parsnips sown in spring will be ready to harvest from late autumn onwards, with their sweetness intensifying after the first frost when stored starches are broken down and converted to sugar, which is why they have that delicious sweetness. This technique is actually the parsnip's defence mechanism against the cold weather as the sugar molecules make the water in the plant cells less likely to freeze.
They store beautifully in the ground over winter with a thick mulch layer to protect them. If you have heavy clay soil though lift them in late autumn and store them in sand or compost in a cool shed.
For overwintered parsnips, be sure to harvest the roots before the tops begin to sprout - never let the plants flower before harvesting.
By sowing parsnips this spring, you’ll be growing your own winter comfort food - perfect for roasting, soups, or simply mashing with butter.
This is an early to mature variety which produces long tapering roots with smooth skins. It is a high yielding variety and is good for heavy soils.
This vigorous variety produces long, slender, smooth roots and is a winner of an RHS Award of Garden Merit.
This is a reliably good and high yielding popular choice for shallow soils producing medium length roots.
Another popular variety, this variety produces large, long tapering roots with a sweet flesh, and is often used on the show bench.