Greenly Garden

Last and first frost dates in St. John's

Canada

In St. John's the last spring frost usually comes around 19 May and the first autumn frost around 10 November, which leaves about 175 frost-free days (median of 2016–2025). Tomato seedlings can go into open ground from 26 June to 21 July.

Last spring frostaround 19 May
First autumn frostaround 10 November
Frost-free days175 days

Median of 2016–2025 for the 25 km grid cell of the city: the last day at or below 0 °C in spring and the first in autumn (ERA5 reanalysis via Open-Meteo). In a cold year a frost can come a week or two later — Greenly warns 48 hours ahead.

When is the last frost in St. John's?

The last frost in St. John's usually comes around 19 May: that is the median of 2016–2025, so in about half of those years the last night at or below 0 °C came later. Hardy crops start before it and frost-tender ones only after it: in the table below arugula can go into open ground from 28 April, while corn waits until 22 June. The first autumn frost follows around 10 November, about 175 days later: harvest or cover frost-tender crops before then.

When to sow and plant

CropSow for seedlingsPlant out in a greenhouseOpen ground
Achocha10 April – 2 August20 May – 11 September10 June – 11 September
Ageratumfrom 10 April—from 26 June
Arugula——sow 28 April – 6 October
Basil16 May – 8 September23 June – 16 October14 July – 16 October
Beet——sow 28 April – 11 September
Bell Pepper24 April – 22 May23 June – 21 July14 July – 21 July
Black-eyed Susanfrom 19 March—from 10 June
Bok Choy15 April – 19 September20 May – 24 October10 June – 24 October
Borage——sow 26 May – 16 September
Broad bean——sow 28 April – 2 August
Broccoli——sow 28 April – 26 July
Brussels Sprouts21 February – 23 June7 April – 7 August28 April – 7 August
Busy Lizziefrom 3 March—from 26 May
Cabbage——sow 28 April – 3 July
Calendula——sow from 28 April
Carrot——sow 28 April – 18 August
Cauliflower24 February – 26 July7 April – 6 September28 April – 6 September
Celeriac4 March – 23 May20 May – 8 August10 June – 8 August
Celery4 March – 2 June20 May – 18 August10 June – 18 August
Celosiafrom 26 Aprilfrom 10 Junefrom 1 July
Chamomile——sow 28 April – 6 September
Chayote5 March – 16 May1 June – 12 August22 June – 12 August
Chickpea——sow 28 April – 23 July
Chicory13 March – 17 August—28 April – 11 September
Chili Pepper24 April – 28 June23 June – 27 August14 July – 27 August
China asterfrom 2 Mayfrom 23 Junefrom 14 July
Chives——sow 28 April – 28 August
Cilantro——sow 28 April – 7 September
Corn——sow 22 June – 23 July
Corn poppy——sow from 28 April
Cosmosfrom 26 Aprilfrom 10 Junefrom 1 July
Cucumber26 May – 29 July23 June – 26 August14 July – 26 August
Daikon——sow 28 April – 4 September
Delphiniumfrom 7 February—from 28 April
Dill——sow 28 April – 17 September
Edging lobeliafrom 18 March—from 10 June
Eggplant24 April – 22 May23 June – 21 July14 July – 21 July
Florence fennel5 April – 2 August20 May – 16 September10 June – 16 September
Foxglovefrom 20 January—from 28 April
Garden sorrel——sow 28 April – 5 September
Green Beans——sow 1 July – 31 July
Hollyhock——sow from 28 April
Hyssop——sow 28 April – 29 July
Kale——sow 28 April – 30 August
Kiwano4 May – 5 August5 June – 6 September26 June – 6 September
Kohlrabi——sow 28 April – 9 September
Leek27 January – 14 May7 April – 23 July28 April – 23 July
Lemon balm——sow 28 April – 1 September
Lettuce——sow 28 April – 14 September
Lisianthusfrom 10 Januaryfrom 7 Aprilfrom 28 April
Lovage——sow from 28 April
Luffafrom 12 Mayfrom 23 Junefrom 14 July
Marigoldfrom 8 Aprilfrom 20 Mayfrom 10 June
Marjoram24 April – 17 August—14 July – 16 October
Melon26 May – 16 July23 June – 13 August14 July – 13 August
Microgreens——sow 1 July – 27 October
Moringa8 May – 22 August2 July – 16 October23 July – 16 October
Moss rosefrom 10 March—from 26 May
Mustard greens——sow 28 April – 26 September
Napa cabbage17 April – 27 August20 May – 29 September10 June – 29 September
Nasturtiumfrom 12 Aprilfrom 20 Mayfrom 10 June
Okra12 May – 10 August23 June – 21 September14 July – 21 September
Oregano6 February – 7 August7 April – 6 October28 April – 6 October
Pansyfrom 10 Februaryfrom 7 Aprilfrom 28 April
Parsley——sow 28 April – 26 August
Parsnip——sow 28 April – 15 July
Peanut17 May – 6 July23 June – 12 August14 July – 12 August
Peas——sow 28 April – 28 August
Petuniafrom 21 Aprilfrom 23 Junefrom 14 July
Physalis21 April – 3 July5 June – 17 August26 June – 17 August
Pumpkin12 May – 4 June23 June – 16 July14 July – 16 July
Purple coneflowerfrom 4 February—from 28 April
Radish——sow 28 April – 11 October
Sage17 February – 3 August7 April – 21 September28 April – 21 September
Scarlet sagefrom 14 April—from 26 June
Snapdragonfrom 1 Februaryfrom 7 Aprilfrom 28 April
Soybean——sow 14 July – 22 August
Spinach——sow 28 April – 16 September
Stevia17 April – 24 June5 June – 12 August26 June – 12 August
Stock——sow from 28 April
Sunflower——sow from 1 July
Sweet alyssum——sow from 28 April
Sweet Corn11 May – 17 August2 June – 8 September23 June – 8 September
Sweet peafrom 24 Februaryfrom 7 Aprilfrom 28 April
Sweet William——sow from 28 April
Swiss Chard——sow 28 April – 11 September
Thyme——sow 28 April – 23 July
Tomato14 April – 30 May5 June – 21 July26 June – 21 July
Turnip——sow 28 April – 13 September
Watercress——sow 28 April – 24 September
Watermelon26 May – 4 July23 June – 1 August14 July – 1 August
Zinniafrom 28 Mayfrom 2 Julyfrom 23 July
Zucchini2 June – 3 August23 June – 24 August14 July – 24 August

Planting out: a week after the last frost once the soil is warm enough for the crop; frost-hardy crops three weeks before it; an unheated greenhouse three weeks earlier. Seedlings are sown so they are ready on that day. Each window starts on the Greenly calendar date and ends on the last day that still leaves the crop’s days to harvest (from its card) before the average first autumn frost, plus six weeks of picking for crops harvested over weeks (tomatoes, peppers, aubergines, cucumbers, courgettes, pumpkins, watermelons, beans) — our rule; earlier in the window is safer.

When the soil warms up in St. John's

The day the top 7 cm of soil first averages each temperature over a week, median of 2016–2025 (ERA5 via Open-Meteo). The soil reaches 10 °C 22 days after the last spring frost and 15 °C 38 days after it.

SoilDateAgainst the last spring frost
5 °C8 May11 days earlier
10 °C10 June22 days later
15 °C26 June38 days later
18 °C14 July56 days later

Frost dates near St. John's

Of the nearest cities on our list, the last spring frost ends earliest in Bangor (24 April) and latest in Charlottetown (10 May).

CityDistanceLast spring frostFirst autumn frost
Charlottetown805 km10 May2 November
Halifax897 km29 April9 November
Moncton933 km1 May4 November
Fredericton1,077 km30 April28 October
Bangor1,268 km24 April3 November

Seeds, seedlings and markets in St. John's

Within 15 km of St. John's OpenStreetMap lists 3 garden centres and 2 markets (collected 20 October 2026). The nearest garden centre to the city centre is The Seed Company, 1 km away.

Places: © OpenStreetMap contributors, ODbL.

What to grow at home in winter in St. John's

Frosts in St. John's usually come from about 10 November to about 19 May. These plants have indoor care in their Greenly cards and are harvested quickly, so they can be sown on a windowsill in winter.

Weather in St. John's by month

Average weather in St. John's over 2016–2025: the warmest month is August. Months that average 20 °C or more by day: August (20.3 °C). Nights average below 0 °C in December–April (-6.9–-0.8 °C). About 1472 mm of rain falls in a year, on 160 days; November is the wettest month (179 mm) and May the driest (92 mm).

MonthDay, °CNight, °CRain, mmRainy days
January0.6-5.616015
February0.1-6.913314
March2-4.512614
April5.2-0.812614
May9.42.29212
June157.811013
July19.712.99812
August20.313.99312
September16.610.811111
October11.66.39712
November7.21.817915
December2.5-2.814716

Average of the daily highs and lows, rain per month and days with at least 1 mm (ERA5 via Open-Meteo, the same grid cell as the frost dates).

Planted in autumn

CropWhen to plant
Bearded Irisby 11 October
Crocus11 October – 1 December
Daffodil11 October – 1 December
Garlic11 October – 1 December
Grape hyacinthby 11 October
Helleboreby 11 October
Hyacinth11 October – 1 December
Lilyby 11 October
Ornamental onionby 11 October
Peonyby 11 October
Saffronby 11 October
Snowdropby 11 October
Tulip11 October – 1 December
Wild garlicby 11 October

From a month before the first autumn frost, so the roots grow before winter, to the late-planting limit on each crop’s page (about two weeks before the ground freezes, by ten years of weather).