GreenlyWhat to plant in September in Canada
Worked out for 29 cities from their own weather and frost dates, by zone.
What to sow and plant in September in Canada, by zone: frost-free, highs of 22–28 °C (Toronto, Hamilton and 4 more): broad bean, peas, onion, spinach, lettuce and 11 more; frost-free, highs of 16–22 °C (Vancouver, Montreal and 18 more): garlic, broad bean, peas, onion, spinach and 15 more; frost possible, highs of 10–16 °C (Whitehorse): garlic, peas, spinach, lettuce, radish and 3 more; frost-free, highs of 10–16 °C (Yellowknife): garlic, radish, arugula and flower bulbs; frost possible, highs below 10 °C (Iqaluit): garlic and flower bulbs.
In Canada, September is autumn.
Frost-free, highs of 22–28 °C: Toronto, Hamilton, London (Canada), Kitchener and 2 more
In September, on average, these cities have highs of 22 to 24 °C and lows of 12 to 16 °C, 28 to 72 mm of rain on 6 to 9 days; the day lasts 12 h 32 min to 12 h 40 min (on the 15th).
No frost in September in 10 years of data: frost-tender crops can go in too, if it is warm enough for them.
| How | What | Where |
|---|---|---|
| plant cloves | Garlic | Toronto and Kitchener |
| sow direct | Broad bean, peas, lettuce, cabbage, broccoli, Swiss chard, beet, parsley, cilantro, arugula, chamomile, dill, kohlrabi, mustard greens | all |
| plant sets | Onion | all |
| start indoors, plant out in October | Spinach | all |
| plant bulbs | Crocus, daffodil, hyacinth, tulip | Toronto and Kitchener |
Compared with August: new — garlic, spinach, broccoli, crocus, daffodil, hyacinth and tulip; no longer sown — zucchini, green beans, watermelon, pumpkin, sweet corn, basil, bok choy, borage and 12 more.
Not starting in September: tomato (March, started indoors), bell pepper (March, started indoors), zucchini (April, started indoors) and green beans (June, sown direct) — dates for Toronto.
Ready to harvest in September in Toronto, if sown in the right month: zucchini (July), green beans (July), watermelon (June), sweet corn (June), basil (July), arugula (August), bok choy (July) and borage (July).
Frost-free, highs of 16–22 °C: Vancouver, Montreal, Calgary, Ottawa and 16 more
In September, on average, these cities have highs of 17 to 22 °C and lows of 7 to 13 °C, 31 to 143 mm of rain on 6 to 13 days; the day lasts 12 h 34 min to 12 h 45 min (on the 15th).
No frost in September in 10 years of data: frost-tender crops can go in too, if it is warm enough for them.
| How | What | Where |
|---|---|---|
| plant cloves | Garlic | Calgary, Winnipeg, Edmonton and 8 more |
| sow direct | Broad bean, cabbage, broccoli | Vancouver, Montreal, Ottawa and 9 more |
| sow direct | Peas, lettuce, arugula, kohlrabi | all |
| plant sets | Onion | Vancouver, Montreal, Ottawa and 9 more |
| start indoors, plant out in October or sow direct | Spinach | Vancouver, Montreal, Calgary and 13 more |
| sow direct | Radish | Vancouver, Calgary, Winnipeg and 14 more |
| sow direct | Swiss Chard, beet, parsley, cilantro, chamomile, dill, mustard greens | Vancouver, Montreal, Calgary and 15 more |
| sow direct | Daikon | Vancouver, Calgary, Winnipeg and 12 more |
| sow direct | Turnip | St. John's |
| plant bulbs | Crocus, daffodil, hyacinth, tulip | Calgary, Winnipeg, Edmonton and 8 more |
Compared with August: new — garlic, turnip, crocus, daffodil, hyacinth and tulip; no longer sown — carrot, zucchini, green beans, sweet corn, basil, chickpea, shallot, bok choy and 4 more.
Not starting in September: tomato (April, started indoors), bell pepper (April, started indoors), zucchini (May, started indoors) and green beans (June, sown direct) — dates for Sherbrooke.
Ready to harvest in September in Sherbrooke, if sown in the right month: broad bean (June), peas (July), cabbage (May), beet (July), zucchini (July), green beans (July), sweet corn (June) and parsley (July).
- Frost dates in Vancouver
- Frost dates in Montreal
- Frost dates in Calgary
- Frost dates in Ottawa
- Frost dates in Winnipeg
- Frost dates in Edmonton
- Frost dates in Quebec City
- Frost dates in Halifax
- Frost dates in Victoria
- Frost dates in Saskatoon
- Frost dates in Sherbrooke
- Frost dates in Trois-Rivières
- Frost dates in Saguenay
- Frost dates in Gatineau
- Frost dates in Regina
- Frost dates in St. John's
- Frost dates in Thunder Bay
- Frost dates in Moncton
- Frost dates in Fredericton
- Frost dates in Charlottetown
Frost possible, highs of 10–16 °C: Whitehorse
In September, on average, Whitehorse has highs of 13 °C and lows of 4 °C, 44 mm of rain on 11 days; the day lasts 12 h 59 min (on the 15th).
September falls in the frost season: frost-tender crops wait. Average first frost: Whitehorse (28 September).
| How | What | Where |
|---|---|---|
| plant cloves | Garlic | Whitehorse |
| sow direct | Peas, spinach, lettuce, radish, arugula, turnip | Whitehorse |
| plant bulbs | Crocus, daffodil, hyacinth, tulip | Whitehorse |
Compared with August: new — turnip; no longer sown — broad bean, onion, cabbage, broccoli, Swiss chard, beet, parsley, cilantro and 5 more.
Not starting in September: tomato (no month outdoors by these rules), bell pepper (no month outdoors by these rules), zucchini (no month outdoors by these rules) and green beans (no month outdoors by these rules) — dates for Whitehorse.
Ready to harvest in September in Whitehorse, if sown in the right month: broad bean (June), peas (July), lettuce (July), radish (August), carrot (July), cabbage (May), broccoli (June) and Swiss chard (July).
Frost-free, highs of 10–16 °C: Yellowknife
In September, on average, Yellowknife has highs of 13 °C and lows of 7 °C, 33 mm of rain on 7 days; the day lasts 13 h 03 min (on the 15th).
No frost in September in 10 years of data: frost-tender crops can go in too, if it is warm enough for them.
| How | What | Where |
|---|---|---|
| plant cloves | Garlic | Yellowknife |
| sow direct | Radish, arugula | Yellowknife |
| plant bulbs | Crocus, daffodil, hyacinth, tulip | Yellowknife |
Compared with August: new — garlic, crocus, daffodil, hyacinth and tulip; no longer sown — peas, spinach, lettuce, Swiss chard, beet, parsley, cilantro, chamomile and 4 more.
Not starting in September: tomato (April, started indoors), bell pepper (April, started indoors), zucchini (May, started indoors), green beans (no month outdoors by these rules), lettuce (April, started indoors), peas (May, sown direct) and spinach (April, started indoors) — dates for Yellowknife.
Ready to harvest in September in Yellowknife, if sown in the right month: broad bean (June), peas (July), lettuce (July), radish (August), carrot (July), cabbage (May), broccoli (June) and Swiss chard (July).
Frost possible, highs below 10 °C: Iqaluit
In September, on average, Iqaluit has highs of 5 °C and lows of 0 °C, 63 mm of rain on 11 days; the day lasts 13 h 06 min (on the 15th).
September falls in the frost season: frost-tender crops wait. Average first frost: Iqaluit (3 September).
Compared with August: no longer sown — peas, spinach, radish, arugula and turnip.
Not starting in September: tomato (no month outdoors by these rules), bell pepper (no month outdoors by these rules), zucchini (no month outdoors by these rules), green beans (no month outdoors by these rules), lettuce (no month outdoors by these rules), peas (July, sown direct) and spinach (May, started indoors) — dates for Iqaluit.
Ready to harvest in September in Iqaluit, if sown in the right month: peas (July), spinach (July), radish (August), Swiss chard (July), beet (July), arugula (August), chamomile (July) and daikon (July).
How we work it out
For each city we use its average weather in September and the months after (highs, lows and rain for 2016–2025, ERA5 reanalysis via Open-Meteo) and its average frost dates. A crop starts in September if the month's mean temperature reaches the minimum soil temperature for germination on its card (we use the mean air temperature as a stand-in for the soil's) and if, over its first months (up to three), the average highs stay within its group's range, with no frost for crops that cannot take it. Crops started indoors count from the month they are planted out.
Temperature groups from Colorado State University Extension: cool-season crops prefer 16–27 °C and lose quality in heat; hardy ones grow in days as cool as 4 °C, semi-hardy ones from 4–10 °C (we use 10 °C); warm-season crops need days above 13 °C, and the most tender (tomato, pepper, aubergine, melon, watermelon, squash) above 16 °C, up to 35 °C. Crops the guide does not name go into the stricter group by their frost hardiness. Broad beans, which the guide does not name, count as hardy: hardy varieties are sown in autumn and overwinter (RHS). Garlic and bulbs: a month before the first frost, and later only while the ground is not frozen (as on each city's page).
This is a general rule from averages: your garden can be a week or two earlier or later, and a greenhouse or a cold frame brings the season forward. Greenly works out the dates for your location.
- Moon planting calendar for September 2027
- What to plant in September: all climates
- Gardening in Canada: guide by region
Other months in Canada
- What to plant in September in the Northeast and Midwest
- What to plant in September in the South
- What to plant in September in Texas
- What to plant in September in California
- What to plant in September in the Pacific Northwest
- What to plant in September in the Mountain West
- What to plant in September in the UK
