What hardiness zone is New Brunswick?

New Brunswick spans plant hardiness zones from about Zone 4 in the north to Zone 6a on the Bay of Fundy coast. New Brunswick is the most continental of the Maritime provinces — away from the coast, its winters are colder than Nova Scotia's or PEI's. The Bay of Fundy coast around Saint John is ocean-moderated to Zone 6a (though with cool, foggy summers), the St. John River Valley and southeast including Fredericton and Moncton are Zone 5b, and the north — the Restigouche and upper Saint John valleys around Edmundston, Bathurst, and Campbellton — drops to Zone 4. Zones are assigned by Natural Resources Canada from winter minimum plus summer heat, rainfall, snow cover, wind, and frost-free days, so a Canadian zone is not identical to the U.S. (USDA) zone of the same number. Check your exact location at planthardiness.gc.ca.

What is New Brunswick's growing zone?

Most New Brunswick gardeners are in Zone 5 — Zone 5b through the populated south and centre (the St. John River Valley, Fredericton, Moncton, and the southeast). The Bay of Fundy coast around Saint John reaches Zone 6a thanks to ocean moderation, while northern New Brunswick — Edmundston, Bathurst, Campbellton, and the higher interior — is Zone 4. So 'New Brunswick's growing zone' is Zone 5 for most, but it swings a full two zones from the warm Fundy coast to the cold north, so confirm your own town on the NRCan map.

What planting zone is Fredericton?

Fredericton is Zone 5b. Sitting inland in the St. John River Valley, it has a more continental climate than the Fundy coast — colder winters but warmer, sunnier summers than foggy Saint John, which actually makes it better for ripening heat-loving crops. Expect an average last spring frost around mid-May and a first fall frost in late September. Choose perennials, shrubs, and trees rated Zone 5 or hardier, and use the warm river-valley summers for tomatoes, peppers, corn, and squash, with frost dates guiding your transplant timing.

What is the warmest hardiness zone in New Brunswick?

The warmest hardiness zone in New Brunswick is Zone 6a, along the Bay of Fundy coast around Saint John, where the ocean holds winter temperatures up. It's a mild-winter zone, but a cool-summer one — Fundy fog keeps summer heat modest, so despite the warm winter zone, heat-loving crops can be slower there than in the sunnier inland river valleys. There is no Zone 7 in New Brunswick. The best all-round growing conditions are arguably in the St. John River Valley (Zone 5b), which trades a slightly colder winter for warmer, sunnier summers.

What zone is northern New Brunswick?

Northern New Brunswick is Zone 4 — the Restigouche and upper Saint John valleys around Edmundston, Bathurst, and Campbellton. Winters are longer and colder than the south, and the growing season is shorter, so northern gardeners choose Zone 4-rated (or hardier) woody plants and lean on season-extension for warm-season vegetables. These northern towns aren't all in our city dataset, so look up your exact location on the Natural Resources Canada Plant Hardiness Zone Map at planthardiness.gc.ca for a precise zone.

How do I find my exact hardiness zone in New Brunswick?

Three ways, most precise first: (1) Use the official Natural Resources Canada Plant Hardiness Zone Map at planthardiness.gc.ca — enter your address or postal code for a location-specific zone that accounts for the province's big coast-to-north range. (2) Use our interactive Zone Finder (growersguide.ca/zone-finder) — click New Brunswick for zones and frost dates. (3) Match to the nearest city in the table on this page. In New Brunswick the key variables are distance from the Bay of Fundy (warmer winters, cooler summers) and latitude/elevation to the north (colder overall). When a plant tag says 'hardy to Zone 5,' choosing one rated Zone 4 is the safe hedge in the north or in valley frost pockets.

Are Canadian hardiness zones the same as USDA zones?

No. The USDA system is based on winter minimum temperature alone. Natural Resources Canada's system factors in seven variables — winter minimum, summer maximum, frost-free period, rainfall, snow cover, and wind — so a Canadian 'Zone 5' is defined differently from a USDA 'Zone 5,' even though the numbers look the same. NRCan does also publish a separate USDA-method map for cross-border comparison. Practical rule for New Brunswick: use the Canadian (NRCan) zone from planthardiness.gc.ca for Canadian-sourced plants and Maritime seed catalogues, and treat a U.S. plant tag's zone as a rough guide only — when in doubt, pick the hardier (lower-numbered) option.

What can I grow in New Brunswick?

New Brunswick's Zone 4–6 range supports a broad palette. The St. John River Valley's warm summers ripen tomatoes, peppers, corn, squash, and even melons in good years; cool-season vegetables (potatoes — a major NB crop — brassicas, roots, leeks, salad greens) thrive province-wide. Hardy tree fruit (apples, plums, hardy pears) and berries (blueberries, especially wild lowbush, plus raspberries and haskap) do well. For ornamentals, match woody plants to your local zone — Zone 5 in the south and centre, Zone 4 in the north — and use hardy Maritime and Prairie-bred shrubs and roses. Use your frost dates for vegetable timing.

NEW BRUNSWICK PLANT HARDINESS ZONES

New Brunswick Hardiness Zones — Zone by City & Region

New Brunswick hardiness zones run from Zone 4 in the north to Zone 6a on the Bay of Fundy coast, with most gardeners in the Zone 5 river valleys and southeast. Find your city's plant zone, frost dates, and growing-season length.

Updated July 2026 · Natural Resources Canada Plant Hardiness Zone Map + Environment and Climate Change Canada normals (1991–2020)

New Brunswick hardiness zones: the most continental Maritime province runs from Zone 4 in the north to Zone 6a on the Bay of Fundy coast. Most gardeners are in Zone 5: Saint John is Zone 6a (mild winters, cool foggy summers), Fredericton and Moncton are Zone 5b, and the north (Edmundston, Bathurst) is Zone 4. Zones come from Natural Resources Canada and are not identical to U.S. (USDA) zones. Find your exact zone at planthardiness.gc.ca or with our Zone Finder.

🍁 New Brunswick Zones at a Glance

Warmest (dataset)

Saint John

Zone 6a

Coolest (dataset)

Moncton

Zone 5b

Most gardeners

Zone 5

the river valleys & southeast

New Brunswick Hardiness Zone by City

Cities below are drawn from our frost-date dataset (Environment and Climate Change Canada normals + Natural Resources Canada zones), sorted from the warmest zone to the coolest. Tap a city with a link for its full month-by-month planting guide.

City	Zone	Last Frost	First Frost	Season
Saint John	6a	May 8	Oct 8	153 days
Fredericton ›	5b	May 17	Sep 26	132 days
Moncton ›	5b	May 15	Sep 28	136 days

Frost dates are historical averages; actual dates vary year to year, so add 1–2 weeks of buffer before transplanting frost-sensitive crops. Inland river-valley frost pockets can run colder than the city reading.

What Zone Is My New Brunswick Town?

The New Brunswick places gardeners look up most, with the plant hardiness zone for each. Dataset cities carry their exact Natural Resources Canada zone; for regions without a dedicated station, we give the zone band and point you to the NRCan map. For a pinpoint answer, check your address at planthardiness.gc.ca or our Zone Finder.

What zone is Saint John?

Zone 6a

The Bay of Fundy coast — the mildest winters in the province, but cool, foggy summers that slow heat-loving crops.

Saint John frost dates & planting ›

What zone is Fredericton?

Zone 5b

The St. John River Valley — colder winters than the coast, but warmer, sunnier summers ideal for ripening crops.

Fredericton frost dates & planting ›

What zone is Moncton?

Zone 5b

The southeast — a solid Zone 5 palette, close to the warmer Northumberland Strait side of the province.

Moncton frost dates & planting ›

What zone is Edmundston & the north?

Zone 4

The Restigouche and upper Saint John valleys (Edmundston, Bathurst, Campbellton) — longer, colder winters; choose Zone 4-hardy plants.

Find your northern town on the Zone Finder ›

New Brunswick's Zones, Warmest to Coldest

Zone 6a — the Bay of Fundy coast. Saint John and the Fundy shore, where the ocean holds winters up. The mildest winter zone in the province — but cool, foggy summers.

Zone 5b — the river valleys & southeast. Fredericton, the St. John River Valley, Moncton, and the southeast. Colder winters than the coast, but warmer, sunnier summers — the province's best all-round growing.

Zone 5a — the upper valleys & interior south. Higher and more inland southern locations — a touch colder than the main Zone 5b belt.

Zone 4 — the north. Edmundston, Bathurst, Campbellton, and the Restigouche and upper Saint John valleys. Longer, colder winters and shorter seasons — Zone 4 plants and season-extension. Confirm your exact zone on the NRCan map.

Why New Brunswick Zones Aren't the Same as U.S. Zones

If you're buying plants or reading growing advice from American sources, don't take a USDA zone at face value. The U.S. system is based on winter minimum temperature alone. Natural Resources Canada's system factors in seven variables — winter minimum, summer maximum, frost-free period, rainfall, snow cover, and wind — so a Canadian "Zone 5" is defined differently from a USDA "Zone 5," even though the number is the same. NRCan publishes a separate USDA-method map for cross-border comparison if you need it.

Practical rule for New Brunswick: use the Canadian (NRCan) zone from planthardiness.gc.ca for Canadian-sourced plants and Maritime seed catalogues, and treat a U.S. plant tag's zone as a rough guide only. In the north and in valley frost pockets, pick the hardier (lower-numbered) option.

Source & how to cite: Zone assignments follow the Natural Resources Canada Plant Hardiness Zone Map (planthardiness.gc.ca); frost dates are Environment and Climate Change Canada climate normals (1991–2020). Enter your address on the NRCan map for a location-specific zone.

New Brunswick City Planting Guides

Your zone tells you what survives the winter; these guides tell you exactly what to sow and transplant, week by week, for your city.

Fredericton Planting Guide ›
Zone 5b · last frost May 17 Moncton Planting Guide ›
Zone 5b · last frost May 15

🍁 Hardiness Zones Across Canada

Ontario →Zones 3b–7a — Windsor to Thunder Bay Quebec →Zones 4b–5b — St. Lawrence valley British Columbia →Zones 4a–9a — Canada’s widest range Alberta →Zones 3b–4b — chinook + elevation Saskatchewan →Zones 2b–3b — Prairie continental Manitoba →Zones 1b–3b — Red River valley Nova Scotia →Zones 5b–6b — ocean-moderated Maritime Prince Edward Island →Zones 5b–6a — ocean-moderated island Newfoundland & Labrador →Zones 4b–6 island; 0–3 Labrador 📍 Find Your Exact Zone →Interactive map + zones-by-city lookup for any Canadian town

Find your exact zone & what to plant now

Click your province on the interactive map, or jump straight to your city's frost-based planting timeline.

🗺️ Interactive Zone Finder 🌱 What to Plant Now ❄️ Frost Date Calculator

New Brunswick Hardiness Zones — Zone by City & Region

🍁 New Brunswick Zones at a Glance

New Brunswick Hardiness Zone by City

What Zone Is My New Brunswick Town?

What zone is Saint John?

What zone is Fredericton?

What zone is Moncton?

What zone is Edmundston & the north?

New Brunswick's Zones, Warmest to Coldest

Why New Brunswick Zones Aren't the Same as U.S. Zones

New Brunswick City Planting Guides

🍁 Hardiness Zones Across Canada

Find your exact zone & what to plant now

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