Now
22°C · Clear
Today
23° / 16°
Soil 6 cm
21°C
First frost
~52 days (Oct 30)
Gardening in Montreal
AI field guide · refreshed weeklyMontreal Gardening: September 8–14 — Harvest Fall Crops, Sow Winter Greens, Prepare for Frost
Zone 5a means your first fall frost arrives around October 30—52 days away. Soil at 21°C is still warm enough for cool-season crops to germinate and establish before soil temps drop below 10°C in late October. You're at day 126 of the frost-free season; use these next 7 weeks to finish tender crops and lock in hardy ones for winter harvest.
Sow outdoors now
Spinach (Spinacia oleracea, e.g. 'Space' or 'Bloomsdale')
Direct-sow now for October–November harvest. Germinates well at 21°C soil; will tolerate light frosts once established.
Arugula (Eruca sativa)
Fast-growing (30–40 days); sow now for late September–October picking. Prefers cool weather and won't bolt as quickly as spring sowings.
Mâche (Valerianella locusta, e.g. 'Verte de Cambrai')
Cold-hardy salad green; sow now for winter harvest under row cover or in cold frame. Germinates slowly at warm temps but thrives once soil cools.
Radish (Raphanus sativus, e.g. 'Cherry Belle' or 'Icicle')
Matures in 25–30 days; sow now for late September–early October harvest before hard frost.
Turnip (Brassica rapa, e.g. 'Purple Top' or 'Hakurei')
Sow now for October harvest; roots sweeten after light frost. Needs 60–70 days but soil temp is still adequate.
Start indoors now
Kale (Brassica oleracea, e.g. 'Lacinato' or 'Winterbor')
Start seeds indoors now for transplant in 3–4 weeks; will mature outdoors before hard frost and tolerate cold storage.
Claytonia/Miner's Lettuce (Claytonia perfoliata)
Start indoors now for transplant in 2 weeks; extremely cold-hardy and will produce through winter under cover in zone 5a.
Microgreens (any brassica or mustard)
Start in trays indoors now for 10–14 day harvest; extends fresh greens through fall and early winter.
Harvest now
Tomato (all types)
Pick all remaining fruit before first frost (Oct 30). Ripen indoors on a sunny windowsill or in a paper bag with an apple.
Pepper (Capsicum annuum)
Harvest all peppers, green or colored; plants will die at first frost. Green peppers will ripen indoors slowly.
Cucumber & Summer Squash
Pick regularly to encourage final flushes before frost. Vines will collapse once temps drop below 10°C.
Beans (snap, pole, dry)
Harvest snap beans now; let dry beans mature on the vine until pods brown and rattle, then shell and store.
Tasks this week
- Deadhead flowers and remove spent annuals to redirect energy; compost disease-free material.
- Mulch around perennials and shrubs with 5–8 cm (2–3 in) of aged compost or shredded leaves to insulate roots before hard frost.
- Divide and transplant spring-blooming perennials (daylilies, hostas, sedums) while soil is still warm and rain is forecast.
- Clean and oil garden tools; drain hoses and shut off outdoor water before first hard freeze.
- Scout for aphids, spider mites, and powdery mildew on remaining crops; remove affected leaves or spray with neem oil if needed.
Watch out for
- Frost risk: Oct 30 is average, but early frosts can arrive in late September. Monitor forecasts and have row cover or frost cloth ready for tender crops.
- Heavy rain (10.4 mm forecast Sept 9) may cause fungal issues; ensure good drainage and air flow around plants.
- Cooling soil (trending toward 10°C by late month) will slow germination; sow cool-season crops by mid-September for best results.
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