What to Plant in April in Canada (Zone 5, 6 & Beyond)

April is the turning point in the Canadian garden. The last frost is still a few weeks away for most of us, but the growing window is opening fast. Miss it and you'll be planting late all season. Time it right and you'll have transplants ready to go the moment the soil warms.

Here's exactly what to do in April, by zone.

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April Planting at a Glance

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What to Start Indoors in April

Brassicas: Broccoli, Cauliflower, and Cabbage

If you're in zone 5b (southern Ontario, Quebec, Ottawa area) or zone 6 (Niagara, southern BC, Windsor), start broccoli, cauliflower, and cabbage indoors in early April. These crops need 4–6 weeks before your last frost:

• Zone 5b (last frost ~May 15): start April 1–7
• Zone 6 (last frost ~May 5): start April 1–7 as well — your window is tight
• Zone 4 (last frost ~May 25): start April 7–14

Brassicas are cool-season crops that prefer to go into cool spring soil. Starting too early produces large plants that stall in cold ground.

Tomatoes and Peppers (Zone 3–4 Only)

If you're in zone 3 (Manitoba, Saskatchewan, northern Ontario — last frost ~June 1) or zone 4 (northern Ontario, Atlantic provinces — last frost ~May 25), April is still within your tomato start window.

• Zone 3 tomatoes: start by April 15 at the latest (6–8 weeks before June 1)
• Zone 4 tomatoes: late March–early April is ideal; April starts are still viable

If you're in zones 5–6 and haven't started tomatoes yet, start immediately — you're already at the edge of the window.

Basil

Basil is extremely cold-sensitive. Start indoors in late April (3–4 weeks before your last frost) and never transplant outside until nighttime temperatures stay consistently above 10°C.

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What to Direct Seed Outdoors in April

Peas

Peas are the first outdoor crop for most Canadian gardeners. They thrive in cool soil and handle a light frost with no trouble.

When to direct sow:

• Zone 6 (last frost ~May 5): sow from late March through April 7
• Zone 5b (last frost ~May 15): sow April 3–21
• Zone 5a/4 (last frost ~May 20–25): sow mid-to-late April

Soil temperature just needs to reach 4°C. If you can work the soil, you can plant peas. Don't wait for warm weather — peas actually prefer cool ground and germinate poorly if it's too warm.

Spinach and Kale

Both are extremely frost-tolerant and can be direct sown as soon as the soil is workable — often late March or early April in zones 5–6.

Sow every 2–3 weeks for continuous harvests. Spinach bolts in summer heat, so your April sowings will be your best of the year.

Lettuce

Start succession sowings of lettuce outdoors from mid-April onward in zones 5–6. Lettuce germinates in cool soil (5°C) and tolerates light frost. Sow a short row every 2 weeks through May for continuous harvests all spring and early summer.

Radishes

Fast-growing (25–30 days) and frost-tolerant. Direct sow radishes from mid-April onward in zones 5–6. They're a useful crop for marking slow-germinating rows like carrots and for filling gaps between larger transplants.

Carrots

Wait until late April in zones 5–6. Carrots need loose, workable soil and soil temps above 7°C. Sow thinly in well-prepared beds — carrots planted in April in zone 5b will be ready to harvest in late June or early July.

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Zone-by-Zone Guide for April

Zone 3 — Manitoba, Saskatchewan, Northern Ontario

Last frost: ~June 1

April is an indoor-only month in zone 3. Focus on:

• Starting tomatoes and peppers indoors if you haven't already (last chance for zone 3)
• Continuing to grow out onions, leeks, and celery (should be at 4–8 weeks by now)
• Starting brassicas indoors in late April (4–6 weeks before June 1)
• Nothing goes outside in zone 3 in April

Zone 4 — Northern Ontario, Atlantic Provinces, BC Interior

Last frost: ~May 25

Late April opens your first outdoor window:

• Spinach and kale can go out in the last week of April with frost protection
• Peas can be direct sown in the last week of April
• Brassica transplants can go outside late April if hardened off and you have frost cloth ready

Zone 5b — Southern Ontario, Quebec, Ottawa

Last frost: ~May 15

April is your most active planting month:

• Start brassicas indoors April 1–7
• Direct sow peas, spinach, and kale starting early-to-mid April
• Succession sow lettuce and radishes from mid-April onward
• Carrots go in late April
• Begin hardening off tomatoes and peppers in late April (transplant mid-May)

Zone 6 — Niagara Peninsula, Southern BC, Windsor

Last frost: ~May 5

• Peas, spinach, and kale are already in the ground or going in now
• Brassica transplants move outside mid-to-late April with light frost protection on cold nights
• Tomatoes and peppers begin hardening off in mid-April (transplant late April–early May)
• Early potatoes can go in the ground in late April

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Frost Risk and Row Cover in April

April weather in Canada is unpredictable. A warm stretch in mid-April can be followed by a -3°C night. Keep frost cloth or row cover on hand.

General guidance:

• Very hardy (kale, spinach, peas, onions): tolerate down to -4°C with no protection
• Semi-hardy (lettuce, radishes, brassica transplants): protect below -2°C
• Tender (tomatoes, peppers, basil): do not go outside until nighttime lows are consistently above 5°C

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What NOT to Plant in April

• Beans: frost-sensitive; direct sow after last frost only
• Squash and zucchini: cold soil stunts them; wait until late May
• Cucumbers: need soil temps above 15°C to germinate well
• Corn: soil needs to reach at least 10°C; plant late May in zones 5–6
• Basil outdoors: one night below 5°C sets it back weeks

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Get Your Exact April Planting Dates

Every frost date above is an average — your specific location within a zone can shift the window by 1–2 weeks. Use the free planting calculator for personalized indoor start dates, transplant dates, and direct sowing windows for 38+ crops.

→ Calculate your April planting dates

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Related Guides

• Canadian Frost Dates by Province and Zone
• When to Plant Vegetables in Canada
• Ontario Planting Dates by Crop
• Succession Planting Calculator