Fall · September 8, 2026

London, Ontario

Great Lakes & St. Lawrence Lowlands·Hardiness zone 6a

Now

24°C · Partly cloudy

Today

26° / 12°

Soil 6 cm

19°C

First frost

~48 days (Oct 26)

Gardening in London

AI field guide · refreshed weekly

London, Ontario Gardening: Early Fall Planting & Harvest Window

You're in zone 6a with 48 days until the average first frost (Oct 26). Soil at 19°C is still warm enough for direct seeding cool-season crops, but frost-sensitive plants need to finish before late October. Spring frost (May 3) means your frost-free season runs roughly May 10–Oct 20 for tender annuals.

Sow outdoors now

  • Spinach (e.g., 'Space' or 'Bloomsdale')

    Direct sow now; germinates in 7–10 days at 19°C soil. Harvest in 40–50 days before frost.

  • Arugula

    Sow thickly; ready to cut in 30–40 days. Tolerates light frost, so successive sowings through September work well.

  • Radish (e.g., 'Cherry Belle')

    Matures in 25–30 days; sow every 2 weeks for continuous harvest through October.

  • Lettuce (e.g., 'Winter Density' or 'Buttercrunch')

    Sow now for fall harvest; cold-hardy varieties can overwinter under row cover if planted by mid-September.

  • Mâche (corn salad)

    Extremely cold-hardy; sow by mid-September for winter grazing. Germinates slowly (14–21 days) but thrives in cool soil.

Start indoors now

  • Kale (e.g., 'Lacinato' or 'Winterbor')

    Start indoors now; transplant in 4–5 weeks for November–December harvest. Flavor improves after frost.

  • Cabbage (e.g., 'January King' or 'Tundra')

    Sow indoors for transplant in 4 weeks; harvest late October through November before hard freeze.

  • Broccoli (e.g., 'Waltham 29' or 'Arcadia')

    Start now for transplant by late September; heads mature in 55–70 days, ideal for October harvest.

Harvest now

  • Tomatoes (all types)

    Pick all remaining fruit, including green ones; ripen indoors or make salsa. Frost will kill plants within 6 weeks.

  • Beans (bush and pole)

    Harvest pods daily; plants will decline as nights cool. Pull plants by late September.

  • Peppers & eggplant

    Collect ripe fruit now; plants slow dramatically in cool nights. Frost-sensitive; expect decline by mid-October.

  • Summer squash & zucchini

    Pick regularly to encourage production; vines weaken as soil cools. Last harvests typically early October.

Tasks this week

  • Deadhead spent flowers and remove diseased foliage to reduce pest overwintering sites.
  • Water deeply after planting cool-season crops; soil at 19°C dries faster than you'd expect.
  • Mulch newly seeded beds lightly to retain moisture and moderate soil temperature swings.
  • Scout for aphids and spider mites on remaining warm-season crops; cool nights slow their reproduction.
  • Cut back perennials (coneflower, black-eyed Susan) after frost blackens foliage, or leave for winter interest and seed.

Watch out for

  • Powdery mildew thrives in cool, humid fall nights—thin crowded plantings and water soil, not leaves.
  • Slugs and snails peak in September; hand-pick at dusk or use beer traps in cool-season beds.
  • Early frost risk if temperatures drop below 0°C unexpectedly; keep frost cloth handy and monitor forecasts after Oct 1.

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