How to Grow Parsnips in Canada

Quick Facts

Factor	Value
Soil pH	6 - 6.8
Germination temp	12°C
Optimal growing temp	15-21°C
Minimum survivable temp	-5°C
Time to harvest	100-120 days
Soil texture	RHS: "deep, light soil that drains readily"; avoid "stony or compacted soil", which causes forked roots.
Drainage	RHS: soil that "drains readily", in an "open, sunny area". Utah State: "sunny locations".
Edible parts	roots

At a Glance

When to Sow -- and Why the Frost Matters More Than the Date

Sow parsnip seed direct once the soil is workable in spring -- there's no fall option in Canada's climate, since the crop needs 100-120 days of real growing season before it's worth lifting. Seed is slow and erratic to germinate (14 to 30 days is normal), so give it time before assuming a row has failed.

The date that actually matters most isn't the sowing date, it's the frost afterward. Parsnips tolerate being left in the ground through a Canadian winter better than most root crops -- RHS and University of Saskatchewan sources agree that a hard frost converts the roots' starches to sugar, so digging in late autumn or even after the ground briefly freezes gives a sweeter root than an early, frost-free harvest would.

Growth Stages

Stage	BBCH	Notes
Sowing & germination	0	Make a shallow 1cm-deep drill, sow thinly or three seeds at 15cm intervals, rows 30cm apart. Notoriously slow and erratic to germinate, needing soil around 12°C -- a mid-spring sowing succeeds far more reliably than an early-spring one on cold ground. RHS.
Thinning	3	Thin to one seedling every 15cm, removing the smaller, weaker ones. RHS.
Root development	4	The long, tapering root develops through summer and into autumn -- a slow-growing crop that spends the whole season bulking up rather than maturing quickly. RHS.
Harvest (after frost)	8	Best left until after the first heavy frost, which intensifies sweetness and flavour by converting starches to sugars. Ease roots out intact with a fork; they can be left in the ground through winter and lifted as needed. RHS.

Soil & Growing Conditions

Water: RHS: water "during dry spells" and keep the soil "evenly moist" to prevent root splitting. Utah State: "1-2 inches per week depending on weather", applied "frequent and uniform".

Soil pH range

6 6.8

Span reflects genuine variation between the cited authorities, not a single agreed figure.

Harvest & Storage

When to pick: RHS: lift once "leaves start to die down in late summer or autumn", and flavour improves "after the first heavy frost". Utah State: harvest "when the roots reach full size".

Storage

RHS: parsnips "can be left in the ground into winter and harvested as required". Utah State: store at "32ºF and 95% relative humidity for two to four weeks".

Diseases

Downy mildew (general)

RHS names parsnips among the vegetables affected by downy mildews.

Pests

Stem and bulb nematode

Ditylenchus dipsaci

RHS names parsnips among affected vegetables, showing "crown and leaf base swelling, rotting, and splitting".

Carrot fly

Psila rosae

RHS: carrot fly affects "Carrot, parsnip, parsley, celeriac and celery".

Sources

The full list of 6 sources behind this guide (FAO EcoCrop, Royal Horticultural Society, Utah State University Extension) is in the references of our UK guide to parsnips; they describe the plant itself, which is the same wherever it grows.