Newfoundland & Labrador Hardiness Zones — Zone by City & Region

The island of Newfoundland is roughly Zone 4b to Zone 6, and the ocean is the whole story. The North Atlantic keeps the island's winters relatively mild for the latitude, so the coasts — especially the Avalon Peninsula around St. John's — sit around Zone 5b to 6. The west coast around Corner Brook is Zone 4b, and the more continental central interior (Gander, Grand Falls) is cooler, around Zone 4 to 5. The catch is summer: Newfoundland's summers are famously cool, short, and foggy, so the growing-season heat — not the winter zone — is usually the real limit on what you can grow. 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. Labrador is a different, far colder story (see below). Check your exact location at planthardiness.gc.ca.

On the island, most gardeners are in Zone 5 — Zone 5b on the ocean-moderated Avalon around St. John's and the southeast coast, Zone 4b on the west coast (Corner Brook), and around Zone 4 to 5 through the cooler central interior. Because the sea moderates the coasts, the winter zone is milder than the latitude suggests, but the cool, short, foggy summers mean season length and heat are the practical limit. Confirm your own community on the NRCan map. Labrador, on the mainland, is much colder — Zone 0 to 3 — and should not be judged by the island's numbers.

St. John's is Zone 5b. On the Avalon Peninsula, surrounded by the Atlantic, it has mild winters for its latitude but very cool, foggy, windy summers and a late spring. Expect an average last spring frost around the start of June and a first fall frost in mid-October. Choose perennials, shrubs, and trees rated Zone 5 or hardier, shelter plants from the relentless wind and salt, and lean on cool-season crops — brassicas, roots, potatoes, salad greens — that don't need much summer heat, giving heat-lovers like tomatoes a sheltered, protected spot or a greenhouse.

The warmest parts of the island are around Zone 6, in the most ocean-sheltered pockets of the Avalon and the south coast, where the surrounding Atlantic holds winter temperatures up. St. John's and the southeast coast are Zone 5b. There is no Zone 7 on the island, and the mild winter zone is deceptive: the cool, short summers mean even a 'warm' Newfoundland zone grows more like a cooler one in practice for heat-loving crops. Season extension — cold frames, tunnels, greenhouses — does more for a Newfoundland garden than chasing a warmer winter zone.

Labrador is far colder than the island of Newfoundland — generally Zone 0 to 3, and it must be treated as its own region. Coastal Labrador (Happy Valley-Goose Bay, and the coast) is roughly Zone 2 to 3, while the interior and the north drop to Zone 1 and Zone 0. This is a subarctic, continental climate with long, hard winters and short seasons, nothing like the ocean-moderated island. Labrador gardeners rely on the hardiest short-season varieties, heavy season-extension, and Zone 1–2 perennials, and make the most of long midsummer daylight. Because these communities aren't in our island dataset, look up your exact location on the Natural Resources Canada map at planthardiness.gc.ca.

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, essential here given the huge gap between the mild island coast and cold Labrador. (2) Use our interactive Zone Finder (growersguide.ca/zone-finder) — click Newfoundland & Labrador for the island's zones and frost dates. (3) Match to the nearest city in the table on this page for the island. On the island, distance from the ocean and wind exposure are the key variables; in Labrador, expect a much colder zone than any island reading. When a plant tag says 'hardy to Zone 5,' choosing one rated Zone 4 is the safe hedge on exposed coasts.

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. This is especially relevant in Newfoundland, where a mild ocean winter could suggest a warm zone but the cool summers pull it back. NRCan does also publish a separate USDA-method map for cross-border comparison. Practical rule: use the Canadian (NRCan) zone from planthardiness.gc.ca for Canadian-sourced plants, and treat a U.S. plant tag's zone as a rough guide only — when in doubt, pick the hardier (lower-numbered) option.

Newfoundland's cool, moist, ocean-moderated climate favours cool-season crops. Root vegetables (potatoes, turnips, carrots, beets — the classic 'root cellar' crops), brassicas (cabbage, kale, Brussels sprouts), leeks, and hardy greens thrive in the cool summers. Rhubarb is practically a provincial emblem, and berries — especially the native partridgeberry, bakeapple (cloudberry), and blueberry — are woven into local food culture. Hardy Zone 5 (or Zone 4 on the west coast) perennials, shrubs, and roses do well with shelter from wind and salt. Heat-loving crops (tomatoes, peppers, cucumbers) need a sheltered spot, a tunnel, or a greenhouse. In Labrador, stick to the hardiest short-season varieties with season extension. Use your frost dates for timing.