Seed Starting Schedule for March 2026 by Canadian Province

Seed Starting Schedule for March 2026 by Canadian Province

March is the month when Canadian gardeners shift from dreaming to doing. Across the country, windowsills and grow light setups come alive with trays of soil and the first green shoots of the season. But timing matters enormously. Starting seeds too early produces leggy, weak transplants. Starting too late means you lose precious growing days in our short season.

This guide breaks down exactly what to start indoors in March 2026, province by province, based on typical last frost dates and growing zone data. If you want precise planting dates for your specific location, use our free planting date calculator to dial in your schedule.

British Columbia (Zones 4-8)

BC is a tale of two climates. Coastal gardeners in the Lower Mainland and Vancouver Island (Zones 7-8) enjoy a last frost date around mid-March to early April, while interior regions like the Okanagan and Prince George (Zones 4-6) wait until mid-May or later.

Coastal BC (Zones 7-8) -- Start in early March:

• Tomatoes and peppers -- These need 6-8 weeks indoors before transplanting. Early March is ideal for a late April or early May transplant.
• Eggplant -- Start alongside peppers. Eggplant needs consistent warmth (24-27 C) to germinate.
• Basil and parsley -- Herbs benefit from an indoor start to get established before outdoor planting.
• Brassicas for spring harvest -- Broccoli, cauliflower, and cabbage can be started now for transplanting in April.

Interior BC (Zones 4-6) -- Start in mid to late March:

• Peppers and hot peppers -- These slow growers need an early start. Mid-March gives them 10+ weeks before a late May transplant.
• Onions and leeks -- If you have not started these already, late March is your last chance. They need 10-12 weeks indoors.
• Early brassicas -- Broccoli and cabbage for late May transplanting.

Alberta (Zones 2-4)

Alberta's last frost dates typically fall between mid-May (Calgary, Zone 4) and early June (Edmonton and northern regions, Zones 2-3). March is prime time for slow-growing crops.

Start in early to mid-March:

• Peppers and hot peppers -- Alberta's short season demands an early start. Peppers need 8-10 weeks indoors.
• Onions from seed -- Varieties like Copra and Cortland need 10-12 weeks to develop strong transplants.
• Celery and celeriac -- These notoriously slow growers benefit from a March 1 start date.
• Artichokes -- If you are growing them as annuals (they need vernalization), start in early March.

Start in late March:

• Tomatoes -- For a late May or early June transplant, late March gives the right 6-8 week window.
• Eggplant -- Start with tomatoes or one week earlier.
• Early herbs -- Parsley, chives, and oregano transplant well and benefit from indoor starting.

Saskatchewan and Manitoba (Zones 1-3)

The prairies have some of the latest frost dates in the country, often not until the last week of May or first week of June. But the long summer days and intense sunshine make up for the late start.

Start in early March:

• Peppers -- Both sweet and hot varieties. Give them the full 10-12 weeks they need.
• Onions and leeks -- Essential to start early. Direct-seeded onions rarely size up in prairie seasons.
• Celery -- Needs 12+ weeks. Start no later than March 1.

Start in late March:

• Tomatoes -- Aim for late March to early April. A June 1 transplant date means 8 weeks of indoor growing.
• Brassicas -- Broccoli, cabbage, and cauliflower for late May transplanting.
• Head lettuce -- Start indoors for transplanting once soil can be worked in May.

Ontario (Zones 4-6)

Ontario's gardening regions range from the mild Niagara Peninsula (Zone 6b) to the much shorter seasons of northern Ontario (Zone 3-4). Most southern Ontario gardeners work with a last frost date around May 15-24.

Start in early March:

• Peppers and hot peppers -- The backbone of many Ontario gardens. Start 10 weeks before your last frost date.
• Onions -- If you missed the February window, early March still works for storage onions.
• Celery and celeriac -- Slow and steady. Start early for the best results.
• Artichokes and cardoon -- Worth trying in Zone 6 with an early start.

Start in mid to late March:

• Tomatoes -- Southern Ontario gardeners should start around March 15-25 for a Victoria Day weekend transplant.
• Eggplant -- Start one week before tomatoes.
• Brassicas -- Broccoli, cauliflower, cabbage, and kohlrabi for May transplanting.
• Swiss chard and kale -- Though these can be direct-seeded later, transplants give you earlier harvests.
• Herbs -- Basil, parsley, cilantro, and dill all benefit from a head start.

For exact dates tailored to your Ontario location, check out our frost dates guide for Canada.

Quebec (Zones 3-5)

Quebec gardeners face a range of conditions, from the relatively mild Eastern Townships and Montreal (Zone 5) to the much shorter seasons of the Saguenay and Abitibi regions (Zone 3). Montreal's last frost date is typically around May 10-15, while Quebec City averages May 20-25.

Start in early March:

• Peppers -- All types. Montreal gardeners can start as early as March 1.
• Onions and leeks -- Critical to start in March for proper bulb development.
• Celery -- Start by March 1 for best results.

Start in mid to late March:

• Tomatoes -- March 15-20 is ideal for Montreal; March 20-25 for Quebec City and regions east.
• Eggplant -- Start with or slightly before tomatoes.
• Brassicas -- Broccoli, cauliflower, and cabbage for late May transplanting.
• Tomatillos and ground cherries -- Popular in Quebec gardens. Same timing as tomatoes.

The Maritimes: New Brunswick, Nova Scotia, PEI (Zones 4-6)

Maritime gardeners deal with cool springs but benefit from the moderating influence of the ocean. Last frost dates range from mid-May (Halifax, Zone 6) to early June (northern New Brunswick, Zone 4).

Start in early to mid-March:

• Peppers -- Start 10 weeks before your expected last frost date.
• Onions and leeks -- An early March start is essential.
• Celery -- Start by mid-March at the latest.

Start in late March:

• Tomatoes -- Late March works well for most Maritime locations.
• Brassicas -- Broccoli, cabbage, cauliflower, and Brussels sprouts.
• Herbs -- Parsley, basil, and chives.
• Flowers -- Snapdragons, marigolds, and zinnias for transplanting in late May.

Tips for Success No Matter Where You Live

Use proper lighting. A south-facing window is rarely enough. Full-spectrum LED grow lights running 14-16 hours per day will produce stocky, healthy transplants.

Bottom heat matters. Heat mats set to 21-27 C dramatically improve germination for tomatoes, peppers, and eggplant. Remove the mat once seedlings emerge.

Do not over-water. Water from the bottom and let the surface dry slightly between waterings. Damping off thrives in constantly wet conditions.

Label everything. Use waterproof markers or stakes. Unlabelled trays become a guessing game fast.

Plan succession plantings. Staggering your starts by 2-3 weeks extends your harvest window. Our season planner can help you map out timing for your entire garden.

Looking Ahead to April

If March is about the slow growers and heat-lovers, April is when things accelerate. Check out our guide on what to plant in April across Canadian zones for the next phase of your seed starting schedule.

The key takeaway: start peppers, onions, and celery in early March no matter where you are in Canada. Tomatoes follow two to four weeks later depending on your province. Get the timing right now, and you will be rewarded with strong, productive transplants when warm weather finally arrives.