Growing Herbs in Canada | Zone 5 & 6 Herb Garden Guide

Herbs are one of the most rewarding additions to a Canadian vegetable garden — many grow quickly, require minimal space, and produce harvests you can use immediately. The challenge for Canadian gardeners is knowing which herbs survive winters in zones 5 and 6, and which ones you need to restart each spring.

This guide covers the most useful culinary herbs for Canadian gardens, sorted by whether they're hardy perennials or annual replants.

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Perennial Herbs for Zone 5 & 6 (Plant Once, Harvest for Years)

These herbs survive Canadian winters in zones 5 and 6 and return each spring without replanting.

Chives

Hardy to: Zone 3 | Sun: Full to part sun

The most reliable perennial herb for Canadian gardens. Chives emerge early in spring — often before anything else in the garden — and produce edible leaves and flowers from May through October. Divide clumps every 3–4 years to keep them productive. Garlic chives are equally cold-hardy and offer a mild garlic flavour.

Thyme

Hardy to: Zone 4 | Sun: Full sun

Common thyme (Thymus vulgaris) is reliably perennial in zone 5 and 6 with good drainage. It struggles in wet, heavy soils over winter — raised beds or sandy soil help significantly. Trim back old growth in spring, not fall, to protect the woody crown.

Oregano

Hardy to: Zone 4–5 | Sun: Full sun

Greek oregano is the most winter-hardy variety for Canadian gardens. It dies back to the ground in winter and re-emerges in late April or May. Grows vigorously and may need dividing every few years. Harvest before flowering for strongest flavour.

Mint

Hardy to: Zone 3 | Sun: Full to part shade

Extremely hardy — possibly too vigorous. Plant mint in a buried container to prevent it from taking over the garden. Excellent for zone 5–6 shaded spots where other herbs struggle.

Lovage

Hardy to: Zone 3 | Sun: Full to part sun

An underused perennial herb with a strong celery-like flavour. Can grow 1.5–2m tall. Leaves, stems, and seeds are all edible. One plant yields abundantly.

Tarragon (French)

Hardy to: Zone 4 | Sun: Full sun

French tarragon is perennial in zones 5–6 with some winter protection (mulch around the crown after hard freeze). Russian tarragon is hardier but lacks flavour — ensure you're getting French (Artemisia dracunculus).

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Annual Herbs to Start Each Season

These herbs don't survive Canadian winters and must be replanted (from seed or transplants) each spring.

Basil

Start indoors: 4–6 weeks before last frost | Transplant: After all frost risk, nights above 10°C

The most frost-sensitive common herb — a single frost kills it. In zone 5 (Ottawa, Calgary) that means outdoor transplanting no earlier than May 20. In zone 6b (Toronto), late April to early May once nights stay warm. Start indoors in late March–early April. Don't rush it outdoors.

Cilantro

Direct sow: 2–4 weeks before last frost | Succession sow: Every 2–3 weeks

Cilantro bolts quickly in heat. Sow directly outdoors in early May across zones 5–6 while nights are still cool. Succession sow every 2–3 weeks through June. Switch to fall sowings in August for a second cool-season harvest.

Dill

Direct sow: After last frost | Notes: Reseed generously if you let it flower

Dill grows quickly from direct-sown seed and doesn't transplant well — direct sow is strongly preferred. One or two plants will reseed themselves for future seasons. Let some plants go to flower and seed to naturalize dill in your garden.

Parsley

Start indoors: 8–10 weeks before last frost | Notes: Biennial — survives one winter in zone 6

Parsley is notoriously slow to germinate (3–4 weeks). Start indoors in late February–early March for zone 5–6. Technically a biennial — zone 6 gardeners can often overwinter parsley with mulch and harvest a second season in spring before it goes to seed.

Summer Savory

Direct sow: After last frost | Sun: Full sun

Less common but worth growing — pairs exceptionally well with beans. Direct sow after last frost. Annual; needs to be replanted each year.

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When to Plant Herbs in Canada

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Tips for Canadian Herb Gardening

Drainage is critical for perennial success. Most perennial herbs (thyme, oregano, tarragon) die in Canadian winters not from cold but from wet, poorly-drained soil. Raise your herb bed 15–20 cm above grade or amend heavily with grit and compost.

Don't fertilize heavily. High-nitrogen soil produces lush, flavourless leaves. Most herbs produce more aromatic oils in lean, well-drained soil. Light compost in spring is sufficient.

Harvest frequently. Regular cutting encourages bushier growth and delays bolting in annual herbs. Never remove more than one-third of a plant at a time.

Mulch perennials for their first winter. Newly planted perennial herbs benefit from 5–8 cm of straw mulch after the ground freezes in late fall. Remove mulch in early spring once temperatures rise above freezing.

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Plan Your Herb Garden Timing

Knowing which herbs to grow is one thing — starting them at the right time for your zone is what gets them in the ground producing before summer heat arrives.

MyGardenPlanner.ca includes herbs in its planting date calculator. Enter your location and zone to see exactly when to start seeds, when to transplant, and what to direct sow this spring.

Get your personalized planting dates at mygardenplanner.ca