What to Plant in June in Canada | Zone 5 & 6 Guide

What to Plant in June in Canada

June is the most productive planting month for Canadian gardeners in zones 5 and 6. Your last spring frost has passed, soil temperatures have warmed above 15°C, and warm-season crops can finally go in the ground without protection. Whether you're transplanting tomato seedlings started in March or direct sowing beans for the first time, June is go-time.

This guide covers what to plant in June across Canada's main growing zones — with specific timing for Ontario, Quebec, the Prairies, and British Columbia.

Understanding Your June Frost Risk

By June 1, most of zones 5 and 6 are frost-free:

• Zone 5a (northern Ontario, parts of Quebec): Last frost around May 15–31. Wait until June 5–10 for tender crops.
• Zone 5b (southern Ontario, BC interior): Last frost around May 10–20. Most transplants safe from June 1.
• Zone 6a/6b (Windsor, Vancouver Island): Last frost April 15–May 5. Full warm-season planting underway by late May.

Check your local frost dates at mygardenplanner.ca/frost-dates-canada before transplanting tender crops.

Direct Sow in June

These crops go directly into the garden from seed in June:

Beans (Bush and Pole)

Direct sow after last frost when soil is above 16°C. Beans hate cold soil — wait until it's consistently warm. Plant every 2–3 weeks through July for continuous harvest. Bush beans mature in 50–60 days; pole beans in 60–70 days.

Cucumbers

Direct sow or transplant in early June in zone 5, or May 25+ in zone 6. Cucumbers need warm soil (18°C+) and a long frost-free window. In zone 5a, choose short-season varieties (55–60 days).

Zucchini and Summer Squash

Direct sow mid-May to early June. These grow fast — a single plant will feed a family. Sow 2–3 seeds per hill, thin to the strongest. Matures in 50–55 days.

Corn

Direct sow corn in early June once soil reaches 16°C. Needs a block planting (minimum 4 rows) for pollination. In zone 5a, choose 65–75 day varieties. Longer-season varieties work in zones 5b and 6.

Basil

Direct sow or transplant after last frost. Basil is extremely frost-sensitive — one cold night will blacken the leaves. Plant in the warmest spot in your garden.

Sunflowers

Direct sow from mid-May through June. Sunflowers are fast (60–90 days) and self-seed readily. Great for cutting gardens and pollinator support.

Transplant in June

These crops should have been started indoors 6–10 weeks earlier and are ready to go out in June:

Tomatoes

Transplant after last frost when nighttime temps stay above 10°C consistently. Zone 5: June 1–10. Zone 6: May 20–June 1. If you haven't transplanted yet, there's still time — tomatoes started indoors in late March still have a full season ahead.

Use the mygardenplanner.ca planting calculator to confirm your tomato transplant date based on your specific zone and first fall frost date.

Peppers and Eggplant

These are the most heat-demanding vegetables and need consistent warmth. Transplant in early June in zone 5b, mid-June in zone 5a. If your soil hasn't hit 18°C, use black plastic mulch to warm it first.

Melons (Zone 6 Only)

In zone 5, melons are a stretch — stick to short-season varieties under 75 days and start indoors 3–4 weeks before transplant. In zone 6, you can direct sow in late May or transplant in June.

Winter Squash and Pumpkins

Transplant seedlings started indoors 3–4 weeks earlier, or direct sow in early June. Winter squash needs 90–120 days to mature — timing matters. In zone 5a, start indoors and transplant to maximize your season.

Cool-Season Crops Still Going In

Not everything in June is a warm-season crop. You can still sow:

• Carrots: Sow every 3 weeks through July for fall harvest
• Beets: Direct sow through mid-June for summer and fall harvests
• Lettuce: Use heat-tolerant varieties; sow in part shade for summer crops
• Swiss chard: Plant through mid-June for summer harvest
• Kale: June sowings will be harvestable into November in most zones

June Garden Tasks

Beyond planting, June is busy:

1. Harden off any remaining transplants — if you haven't moved seedlings outside full-time, do it gradually over 7–10 days
2. Mulch once soil is warm — 2–3 inches of straw or wood chips conserves moisture and suppresses weeds
3. Set up trellises before climbing crops need them — beans and cucumbers grow fast
4. Thin direct-sown crops — crowded seedlings compete for nutrients and light

Plan Your Whole Season

Knowing what to plant in June is just one piece. Use mygardenplanner.ca to build a full planting schedule from seed start to harvest — the calculator works backwards from your target harvest dates so you never miss a planting window.

For zone-specific dates and crop-by-crop timing across all Canadian provinces, visit mygardenplanner.ca/planting-dates.