How to Grow Burdock (Gobo) Canada

At a Glance

Quick Facts

Factor	Value
Soil texture	clay, loam or sand (RHS)
Drainage	well-drained
Lifecycle	biennial
Edible parts	roots

Soil & Growing Conditions

Water: moist but well-drained (RHS)

Growth Stages

Stage	BBCH	Notes
Sowing	0	Sow seed in autumn or early spring, pre-soaked or scarified to improve germination, or sow in a tray and transplant before the tap-root develops (RHS).
Taproot development	3	Develops a long, deep taproot alongside large downy foliage; cultivated gobo is spaced 50-60cm apart (NC State Extension).
First-year root harvest	8	First-year roots are harvested by late autumn before they become too fibrous (RHS; NC State Extension).
Second-year flowering	6	In its second year, unharvested plants produce purplish thistle-like flowerheads followed by characteristic brown burr seedheads (RHS).

Harvest & Storage

When to pick: Harvest the long first-year taproot by late autumn, before it becomes too fibrous; sown from seed in summer with plants spaced 50-60cm (about 2ft) apart (RHS; NC State Extension).

Diseases

Powdery mildew

low

NC State Extension: occasional powdery mildew.

Pests

Aphids

low

Aphididae (various spp.)

NC State Extension: occasional aphids.

What the research guides add

Burdock is grown as a root vegetable in Asia, and NC State is blunt about its other side: it is a weed.

• A biennial: the first year forms a short, dense rosette of leaves; in its second year it bolts to 2 to 10 feet and its tap roots grow to depths of 3 feet. (NC State Extension)
• It prefers full sun and moist, well-drained soil rich in organic matter and nitrogen. (NC State Extension)
• In Asia it is cultivated for its edible roots. Cultivated plants are sown from seed in summer and the first-year roots are harvested by late autumn, before they become too fibrous. (NC State Extension)
• It can become invasive and is extremely difficult to eradicate because of its deep tap roots and the long-lived seed; the burs are very hard to remove from fur and clothing. (NC State Extension)

Burdock (gobo) in Canada: climate data

Frost dates and frost-free days are the median values for the stations in Environment and Climate Change Canada climate normals with the highest data-quality rating (1981–2010 normals).

Sources for this section

• NC State Extension: Arctium lappa (Plant Toolbox)

Section researched and checked on 25 October 2026 by the SoilCommander Editorial Team. How we check facts: editorial policy.

Sources

The full list of 3 sources behind this guide (NC State Extension, Plants For A Future (PFAF), Royal Horticultural Society) is in the references of our UK guide to burdock (gobo); they describe the plant itself, which is the same wherever it grows.