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Home & garden.

14 July 2021

How to grow parsnips

A fantastic winter veg, roast dinners wouldn't be the same without parsnips. Discover our Best Buy varieties and learn how to grow them.
CT
Ceri Thomas
Parsnips

Modern varieties of parsnips have been bred to produce short fat roots rather than long tapering ones. We were looking for varieties with a good crop of unblemished, smooth-skinned roots, making for little waste in the kitchen.

How to grow parsnips: month by month

January
February
March
April
May
June
HARVESTING
HARVESTING
SOWING/HARVESTING
SOWING/HARVESTING
SOWING
GROWING
July
August
September
October
November
December
HARVESTING
HARVESTING
HARVESTING
HARVESTING
HARVESTING
HARVESTING

Best parsnip varieties

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Best Buy parsnips
What it looks like
Variety name
Weight of 20 roots
2.5kg
The first F1 hybrid parsnip to be produced and still one of the best. It was one of the biggest croppers in our trial. It produced uniform wedge-shaped roots, mostly more than 4cm wide and 16cm long, with little wastage in the kitchen. It was almost untouched by the crown rot that affected other varieties we trialled and is said to have good resistance to parsnip canker.
What it looks like
Variety name
Weight of 20 roots
1.5kg
This is one of a recent series of hybrid parsnip varieties to have been named after a pointed weapon. This variety sped to an impressive crop of baby parsnips in July. All the roots were useable, with no crown rot, by December - although they hadn’t grown much bigger in the meantime. The roots were thin-shouldered, tapering and uniform in shape.
What it looks like
Variety name
Weight of 20 roots
2.4kg
A recently bred variety, it bulked up very quickly, giving the biggest crop of roots in July, though they were too large to class as ‘baby’. They had put on a little more weight by December, but our second sowing and overwintered crop was disappointing. There were few unusable roots and it was unspoilt by crown rot. Roots were broad-shouldered and slightly bulbous.

How we test parsnips

We trialled 16 varieties - most, but not all, modern F1hybrids (the offspring of crosses between selected parent strains) – including  ‘Tender and True’, an old favourite. The seed was sown direct into prepared ground at our test site in April. A double row, 4m long with 35cm between rows, was sown of each variety. The seedlings were thinned to leave a plant every 7.5-10cm. We had planned for 80 plants of each variety so we could harvest and assess 20 roots in July (as baby parsnips), 20 in December (for Christmas dinner) and 20 in March (to check how well they survived the winter). Because parsnips are susceptible to carrot root fly, we covered the plots with fleece. .

When to sow

March to April is the best time to sow parsnips, although you can sow as late as May (which may work best in colder areas.)

To grow good parsnips you will need a deep, stone-free and free-draining soil, preferably sandy. If your soil isn’t suitable, consider growing in raised beds filled with sieved soil to give a depth of at least 20cm. Like carrots, parsnips need little in the way of nutrients. Don’t grow them on freshly manured ground or the roots will fork. 

Seed must be fresh, but even then it can be slow to germinate. Be patient: mark the rows and weed carefully. Sow the seed thinly and thin out excess seedlings to leave one every 7.5-10cm. An alternative is to sow a couple of seeds at this spacing and snip off all but the best seedling. 

Timing is tricky. Though it’s tempting to sow early, the soil may not be warm enough some years. Water the seed bed to promote even germination. Thereafter, don’t water the surface so that the roots are encouraged to go down in search of moisture.

Cover the bed with fine insect-roof mesh to keep out carrot fly.

How and when to harvest

Harvest in: July to April

You can start to harvest roots as soon as they reach 2cm across, from July or August onwards, but leave the majority for Christmas and winter. The roots should start to taste sweeter after a couple of frosts. Use a fork to lift the roots without breaking them.

Parsnips will remain in good condition in the ground until March or April, when they will start to regrow. As a biennial, a parsnip will produce a huge flowerhead in its second year. In a severe winter, cover the row with straw or several layers of fleece; alternatively lift your crop and store in paper sacks in a cool but frost-free place. 

Common growing problems

Carrot root fly

The larvae of carrot fly can burrow into the roots and cause damage so protect your plants by growing them under fine insect-proof mesh.

Read more about carrot fly

Parsnip canker

Black or orange patches on the roots are a sign of parsnip canker. The patches usually occur near the shoulder of the roots and the crown of the plants. In severe cases, the roots crack and rot. 

Read more about parsnip canker.