In Lethbridge, the average last spring frost is May 24 and the average first fall frost is Sep 12, a growing season of about 111 days (zone 4b). Start tomatoes indoors around Apr 12 and move them outside from Jun 7. Plant garlic Sep 19 to Sep 26, one to two weeks after the first fall frost.
Lethbridge at a glance
- Last spring frost
- May 24 (average)
- First fall frost
- Sep 12 (average)
- Frost-free season
- About 111 days
- Hardiness zone
- 4b (NRCan)
- Weather stations
- Vauxhall, Claresholm and Milk River, 1991 to 2020 normals. GrowSmart's dates are the median of these stations, to within 3 days
An average frost date means frost is still possible after it in about half of years. GrowSmart times tender crops like tomatoes, peppers and basil after this date, not on it.
What to plant in Lethbridge this month (January)
Nothing is scheduled to be sown or planted in Lethbridge in January. Next up: start onions indoors on Mar 15.
What to plant in Lethbridge this month (February)
Nothing is scheduled to be sown or planted in Lethbridge in February. Next up: start onions indoors on Mar 15.
What to plant in Lethbridge this month (March)
- Start onions indoors: Mar 15
Coming up in early April: start tomatoes indoors (Apr 12), start peppers indoors (Apr 12), start eggplant indoors (Apr 12) and start lettuce indoors (Apr 12).
What to plant in Lethbridge this month (April)
- Start tomatoes indoors: Apr 12
- Start peppers indoors: Apr 12
- Start eggplant indoors: Apr 12
- Start lettuce indoors: Apr 12
- Start kale indoors: Apr 19
- Start broccoli indoors: Apr 19
- Start cabbage indoors: Apr 19
- Start basil indoors: Apr 26
Coming up in early May: direct sow spinach (May 3), direct sow peas (May 3), direct sow radishes (May 3), transplant lettuce (May 10), direct sow carrots (May 10), start cucumbers indoors (May 10), start zucchini indoors (May 10) and start winter squash indoors (May 10).
What to plant in Lethbridge this month (May)
- Direct sow spinach: May 3
- Direct sow peas: May 3
- Direct sow radishes: May 3
- Transplant lettuce: May 10
- Direct sow carrots: May 10
- Start cucumbers indoors: May 10
- Start zucchini indoors: May 10
- Start winter squash indoors: May 10
- Direct sow beets: May 17
- Transplant kale: May 17
- Transplant broccoli: May 17
- Transplant cabbage: May 17
- Direct sow potatoes: May 17
- Transplant onions: May 24
- Transplant cucumbers: May 31
- Transplant zucchini: May 31
- Transplant winter squash: May 31
- Direct sow beans: May 31
Coming up in early June: transplant tomatoes (Jun 7), transplant peppers (Jun 7), transplant eggplant (Jun 7) and transplant basil (Jun 7).
What to plant in Lethbridge this month (June)
- Transplant tomatoes: Jun 7
- Transplant peppers: Jun 7
- Transplant eggplant: Jun 7
- Transplant basil: Jun 7
Coming up in early July: sow peas for a fall harvest (Jul 4) and sow kale for a fall harvest (Jul 4).
What to plant in Lethbridge this month (July)
- Sow peas for a fall harvest: Jul 4
- Sow kale for a fall harvest: Jul 4
- Sow lettuce for a fall harvest: Jul 18
- Sow spinach for a fall harvest: Jul 25
Coming up in early August: sow radishes for a fall harvest (Aug 8).
What to plant in Lethbridge this month (August)
- Sow radishes for a fall harvest: Aug 8
What to plant in Lethbridge this month (September)
- Plant garlic: Sep 19 to Sep 26
What to plant in Lethbridge this month (October)
Nothing is scheduled to be sown or planted in Lethbridge in October. Next up: start onions indoors on Mar 15.
What to plant in Lethbridge this month (November)
Nothing is scheduled to be sown or planted in Lethbridge in November. Next up: start onions indoors on Mar 15.
What to plant in Lethbridge this month (December)
Nothing is scheduled to be sown or planted in Lethbridge in December. Next up: start onions indoors on Mar 15.
Lethbridge planting calendar
| Crop | Start indoors | Plant outside | Harvest |
|---|---|---|---|
| Tomatoes | Apr 12 | Transplant Jun 7 | From Aug 24 |
| Peppers | Apr 12 | Transplant Jun 7 | From Aug 18 |
| Eggplant | Apr 12 | Transplant Jun 7 | From Aug 21 |
| Basil | Apr 26 | Transplant Jun 7 | From Jul 19 |
| Onions (from seed) | Mar 15 | Transplant May 24 | From Sep 1 |
| Lettuce | Apr 12 | Transplant May 10Fall: direct sow Jul 18 | From Jun 19Fall: from Aug 27 |
| Spinach | n/a | Direct sow May 3Fall: direct sow Jul 25 | From Jun 12Fall: from Sep 3 |
| Peas | n/a | Direct sow May 3Fall: direct sow Jul 4 | From Jul 2Fall: from Sep 2 |
| Radishes | n/a | Direct sow May 3Fall: direct sow Aug 8 | From May 28Fall: from Sep 2 |
| Carrots | n/a | Direct sow May 10 | From Jul 19 |
| Beets | n/a | Direct sow May 17 | From Jul 11 |
| Kale | Apr 19 | Transplant May 17Fall: direct sow Jul 4 | From Jul 11Fall: from Aug 28 |
| Broccoli | Apr 19 | Transplant May 17 | From Jul 21 |
| Cabbage | Apr 19 | Transplant May 17 | From Jul 26 |
| Cucumbers | May 10 | Transplant May 31 | From Jul 25 |
| Zucchini | May 10 | Transplant May 31 | From Jul 20 |
| Winter squash | May 10 | Transplant May 31 | From Aug 29 |
| Beans | n/a | Direct sow May 31 | From Jul 25 |
| Potatoes | n/a | Direct sow May 17 | From Aug 5 |
| Garlic | n/a | Plant cloves Sep 19 to Sep 26 | Around Aug 16 the next year |
Dates are for one planting of each crop, from Lethbridge's average frost dates. Tomatoes are indeterminate, lettuce is looseleaf and beans are bush beans. Harvest dates are when the first picking is usually ready. Garlic follows University of Minnesota Extension (see below).
Fall planting in Lethbridge
Plant garlic Sep 19 to Sep 26. That is one to two weeks after Lethbridge's average first fall frost of Sep 12, the timing University of Minnesota Extension recommends, so the cloves root before winter without sending shoots up. Harvest comes around Aug 16 the following summer. How to plant garlic in Lethbridge.
Shallots: GrowSmart's plan has you plant shallot sets in fall in zone 5 and warmer, and in spring in colder zones.
Cool-season crops GrowSmart schedules for a fall harvest in Lethbridge:
- Peas: sow Jul 4, ready from about Sep 2
- Kale: sow Jul 4, ready from about Aug 28
- Lettuce: sow Jul 18, ready from about Aug 27
- Spinach: sow Jul 25, ready from about Sep 3
- Radishes: sow Aug 8, ready from about Sep 2
Nearby planting calendars
Lethbridge planting questions
When is the last frost in Lethbridge?
The average last spring frost in Lethbridge is May 24, and the average first fall frost is Sep 12, from 1991 to 2020 climate normals at 3 nearby weather stations. Frost is still possible after the spring date in about half of years.
When should I start tomato seeds in Lethbridge?
Start tomatoes indoors around Apr 12, 8 weeks before moving them outside around Jun 7, which is two weeks after the average last frost.
What can I plant in Lethbridge in fall?
Garlic goes in Sep 19 to Sep 26. For fall harvests, sow peas and kale around Jul 4, lettuce around Jul 18, spinach around Jul 25 and radishes around Aug 8.