GreenlyWhat to plant in August in Canada
Worked out for 29 cities from their own weather and frost dates, by zone.
What to sow and plant in August in Canada, by zone: frost-free, highs above 28 °C (Kelowna): zucchini, green beans, basil, bok choy and borage; frost-free, highs of 22–28 °C (Toronto, Vancouver and 22 more): broad bean, peas, onion, lettuce, cabbage and 11 more; frost-free, highs of 16–22 °C (St. John's, Whitehorse and 1 more): broad bean, peas, onion, spinach, lettuce and 13 more; frost-free, highs of 10–16 °C (Iqaluit): garlic, peas, spinach, radish, arugula and 2 more.
In Canada, August is summer.
Frost-free, highs above 28 °C: Kelowna
In August, on average, Kelowna has highs of 30 °C and lows of 16 °C, 14 mm of rain on 4 days; the day lasts 14 h 30 min (on the 15th). A dry month: whatever is sown needs watering.
No frost in August in 10 years of data: frost-tender crops can go in too, if it is warm enough for them.
| How | What | Where |
|---|---|---|
| sow direct | Zucchini, green beans, basil, bok choy, borage | Kelowna |
Compared with July: no longer sown — cucumber, watermelon, pumpkin, sweet corn, chayote, corn, Florence fennel, kiwano and 6 more.
Not starting in August: tomato (March, started indoors), bell pepper (March, started indoors), lettuce (September, sown direct), peas (September, sown direct) and spinach (September, started indoors) — dates for Kelowna.
Ready to harvest in August in Kelowna, if sown in the right month: cabbage (April), green beans (June), sweet corn (May), bok choy (June), borage (June), corn (May), Florence fennel (May) and Napa cabbage (June).
Frost-free, highs of 22–28 °C: Toronto, Vancouver, Montreal, Calgary and 20 more
In August, on average, these cities have highs of 22 to 27 °C and lows of 11 to 19 °C, 22 to 144 mm of rain on 4 to 15 days; the day lasts 13 h 56 min to 14 h 52 min (on the 15th).
No frost in August in 10 years of data: frost-tender crops can go in too, if it is warm enough for them.
| How | What | Where |
|---|---|---|
| sow direct | Broad bean, peas, cabbage, beet, parsley, cilantro, arugula, chamomile, dill, mustard greens | Toronto, Vancouver, Montreal and 20 more |
| plant sets | Onion | Toronto, Vancouver, Montreal and 20 more |
| start indoors, plant out in September | Spinach | Calgary, Edmonton, Saguenay and 2 more |
| start indoors, plant out in September or sow direct | Lettuce, kohlrabi | Toronto, Vancouver, Montreal and 20 more |
| sow direct | Carrot, kale, parsnip | Sherbrooke, Saguenay, Thunder Bay and 1 more |
| start indoors, plant out in October or sow direct | Broccoli | Vancouver, Edmonton, Victoria and 4 more |
| start indoors, plant out in September or sow direct | Swiss Chard | Toronto, Vancouver, Montreal and 19 more |
| sow direct | Zucchini, green beans, basil, bok choy, borage | Toronto, Montreal, Ottawa and 5 more |
| sow direct | Watermelon, pumpkin, chayote, Florence fennel, kiwano, moringa, Napa cabbage, peanut, soybean | Hamilton, London (Canada) and Windsor |
| sow direct | Sweet Corn, corn | Montreal, Ottawa, Hamilton and 3 more |
| sow direct | Chickpea | Toronto, Vancouver, Montreal and 18 more |
| plant sets | Shallot | Toronto, Vancouver, Montreal and 18 more |
| sow direct | Luffa | Hamilton and Windsor |
| sow direct | Okra | Windsor |
Compared with July: new — spinach; no longer sown — cauliflower, cucumber, melon and achocha.
Not starting in August: tomato (April, started indoors) and bell pepper (April, started indoors) — dates for Moncton.
Ready to harvest in August in Moncton, if sown in the right month: broad bean (May), peas (June), beet (June), green beans (June), parsley (June), cilantro (June), arugula (July) and bok choy (June).
- Frost dates in Toronto
- 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 Hamilton
- Frost dates in London (Canada)
- Frost dates in Gatineau
- Frost dates in Kitchener
- Frost dates in Windsor
- Frost dates in Regina
- Frost dates in Thunder Bay
- Frost dates in Moncton
- Frost dates in Fredericton
- Frost dates in Charlottetown
Frost-free, highs of 16–22 °C: St. John's, Whitehorse and Yellowknife
In August, on average, these cities have highs of 19 to 20 °C and lows of 9 to 14 °C, 46 to 93 mm of rain on 9 to 12 days; the day lasts 14 h 19 min to 16 h 08 min (on the 15th).
No frost in August 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 | Whitehorse |
| sow direct | Broad bean, cabbage, broccoli | St. John's and Whitehorse |
| sow direct | Peas, lettuce, radish, Swiss chard, beet, parsley, cilantro, arugula, chamomile, daikon, dill, kohlrabi, mustard greens | all |
| plant sets | Onion | St. John's and Whitehorse |
| start indoors, plant out in September or sow direct | Spinach | all |
| sow direct | Carrot, kale, parsnip | St. John's |
| plant sets | Shallot | St. John's |
| plant bulbs | Crocus, daffodil, hyacinth, tulip | Whitehorse |
Compared with July: new — garlic, crocus, daffodil, hyacinth and tulip; no longer sown — cauliflower and chickpea.
Not starting in August: tomato (April, started indoors), bell pepper (April, started indoors), zucchini (May, started indoors) and green beans (no month outdoors by these rules) — dates for Yellowknife.
Ready to harvest in August in Yellowknife, if sown in the right month: broad bean (May), peas (June), lettuce (June), carrot (June), Swiss chard (June), beet (June), parsley (June) and cilantro (June).
Frost-free, highs of 10–16 °C: Iqaluit
In August, on average, Iqaluit has highs of 11 °C and lows of 5 °C, 76 mm of rain on 13 days; the day lasts 16 h 24 min (on the 15th).
No frost in August 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 | Iqaluit |
| sow direct | Peas, spinach, radish, arugula, turnip | Iqaluit |
| plant bulbs | Crocus, daffodil, hyacinth, tulip | Iqaluit |
Compared with July: new — garlic, crocus, daffodil, hyacinth and tulip; no longer sown — broad bean, onion, cabbage, broccoli, Swiss chard, beet, chamomile, daikon and 3 more.
Not starting in August: 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) and lettuce (no month outdoors by these rules) — dates for Iqaluit.
Ready to harvest in August in Iqaluit, if sown in the right month: radish (July), arugula (July), dill (July) and mustard greens (July).
How we work it out
For each city we use its average weather in August 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 August 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.
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- What to plant in August: all climates
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