Cold hardiness & minimum temperature

Is Parsnip 'Hollow Crown' (Pastinaca sativa 'Hollow Crown')cold hardy? Hardiness zone & min temp

Also called Hollow Crown parsnip, heirloom parsnip.

More about parsnip 'hollow crown'

About Parsnip 'Hollow Crown'

Pastinaca sativa 'Hollow Crown' · also called Hollow Crown parsnip, heirloom parsnip · edible

'Hollow Crown' is a classic open-pollinated heirloom parsnip, named for the slight depression at its crown. It produces long, tapering, sweet white roots with excellent flavour and is a reliable home-saved variety, though less canker-resistant than modern F1 hybrids. Direct-sow in spring on deep, stone-free soil and lift from autumn through winter after frost has sweetened the roots.

Cold limit: USDA 2-9 (grown as an annual; roots overwinter in-ground in milder zones) · RHS H6 (7-18°C)

What parsnip 'hollow crown''s hardiness rating actually means

Hardiness works differently for parsnip 'hollow crown': it is grown as a seasonal crop, not overwintered. The question is not "what zone" but "how long is your frost-free growing window". Its RHS rating of H6 means: Hardy throughout the UK and northern Europe. On the US scale that maps to USDA 2-9 (grown as an annual; roots overwinter in-ground in milder zones) — the zones where it can be left outdoors year-round.

New to these scales? The USDA hardiness zone map explained covers how the zone numbers work, and you can find your own zone with the zone finder.

Minimum temperature — and what happens below it

As an annual crop, its "minimum temperature" is the first hard frost — that is the end of the plant's life, not a survivable low. Many types are also damaged by light frost (around 0 °C).

Concretely, for parsnip 'hollow crown' as it gets too cold:

Light frost (around 0 to −2 °C) damages or kills tender summer crops outright; cold-hardy types take a few degrees of frost.
The plant does not "survive winter" — its life cycle simply ends, by design, when frost arrives or it finishes cropping.
A surprise late spring frost can also kill young transplants set out too early, before the season even starts.

Can parsnip 'hollow crown' go outside or overwinter — and where?

Time it to your frost dates: sow or plant out after the last spring frost, and aim to harvest before the first autumn frost.
In short-season zones, start it indoors or under cover to stretch the effective growing window.
Hardier crops in this group can be sown for an autumn or overwintered harvest in mild zones — check the specific crop.

Work back from your local frost dates with the frost-date calculator: the last spring frost and first autumn frost are what really decide when parsnip 'hollow crown' can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H6 figure above.

Frost protection for borderline parsnip 'hollow crown'

Parsnip 'Hollow Crown' is right on a hardiness edge in many gardens, so if you are pushing it, these measures buy it the margin it needs:

Use fleece, cloches or a cold frame at each end of the season to dodge a borderline frost and add growing weeks.
Have row cover ready for an unexpected late spring or early autumn frost.
Know your local last- and first-frost dates and count back the crop’s days-to-maturity to schedule the sowing.

Parsnip 'Hollow Crown' hardiness — frequently asked questions

Is parsnip 'hollow crown' cold hardy?

Hardiness works differently for parsnip 'hollow crown': it is grown as a seasonal crop, not overwintered. The question is not "what zone" but "how long is your frost-free growing window". A seasonal crop, not a perennial. Parsnip 'Hollow Crown' is grown 2-9 (grown as an annual; roots overwinter in-ground in milder zones); you sow after the last frost and harvest before the first one, then start again next year.

What is the minimum temperature parsnip 'hollow crown' can survive?

As an annual crop, its "minimum temperature" is the first hard frost — that is the end of the plant's life, not a survivable low. Many types are also damaged by light frost (around 0 °C).

What hardiness zone is parsnip 'hollow crown'?

Parsnip 'Hollow Crown' is rated USDA 2-9 (grown as an annual; roots overwinter in-ground in milder zones) and RHS H6 — Hardy throughout the UK and northern Europe.

Can parsnip 'hollow crown' survive winter outside?

Time it to your frost dates: sow or plant out after the last spring frost, and aim to harvest before the first autumn frost. In short-season zones, start it indoors or under cover to stretch the effective growing window. Hardier crops in this group can be sown for an autumn or overwintered harvest in mild zones — check the specific crop.

How do I protect parsnip 'hollow crown' from frost?

Use fleece, cloches or a cold frame at each end of the season to dodge a borderline frost and add growing weeks. Have row cover ready for an unexpected late spring or early autumn frost. Know your local last- and first-frost dates and count back the crop’s days-to-maturity to schedule the sowing.