Starting seeds indoors is a great way to get a head start on the growing season, especially in Canada, where short summers can limit plant growth. To ensure success, it’s important to time your seed starting based on your local last frost date. Here’s how to determine the best time to start your seeds indoors.
Understanding the Last Frost Date
The last frost date is the estimated date in spring when the risk of frost has passed. This varies widely across Canada:
- West Coast (Vancouver, Victoria): Early March to mid-April
- Prairies (Calgary, Edmonton, Winnipeg): Late May to early June
- Central Canada (Toronto, Ottawa, Montreal): Mid to late May
- Atlantic Canada (Halifax, St. John’s): Late May to early June
- Northern Canada: June or later
You can check your local last frost date through resources like the Government of Canada’s agricultural websites or the Farmer’s Almanac.
General Guidelines for Starting Seeds Indoors
Most seed packets provide recommendations on when to start seeds indoors, typically stated as “X weeks before the last frost date.”
| Plant Type | Weeks Before Last Frost |
|---|---|
| Peppers | 8-10 weeks |
| Tomatoes | 6-8 weeks |
| Broccoli | 5-7 weeks |
| Lettuce | 4-6 weeks |
| Cucumbers | 3-4 weeks |
| Squash | 3-4 weeks |
| Herbs (Basil, Parsley) | 6-8 weeks |
How to Calculate Your Start Date
- Find your last frost date. Use online databases or local gardening centers to determine the approximate date.
- Check your seed packet. Identify how many weeks before the last frost you should start the seeds.
- Count backward. Using a calendar, count the recommended weeks back from your frost date to determine your planting date.
Additional Tips for Success
- Use grow lights to provide consistent light if natural sunlight is insufficient.
- Keep soil temperature warm (especially for peppers and tomatoes) using a heat mat.
- Harden off seedlings by gradually exposing them to outdoor conditions 7-10 days before transplanting.
By aligning your seed starting schedule with your local last frost date, you can maximize your growing season and ensure strong, healthy plants for the garden. Happy planting!
