Now
20°C · Clear
Today
21° / 13°
Soil 6 cm
16°C
First frost
~33 days (Oct 11)
Gardening in Sherbrooke
AI field guide · refreshed weeklySherbrooke Garden Guide: Early September — Harvest Season Begins, Winter Crops Go In
You're in zone 5a with 33 days until your average first frost (October 11). Soil is cooling fast at 16°C—perfect for seeding cool-season crops but too cold for warm-season germination. Spring frost came May 13, so you've had a solid 118-day growing season. Expect hard freezes by mid-October; plan accordingly.
Sow outdoors now
Spinach (Spinacia oleracea 'Space' or 'Bloomsdale')
Sow directly into beds now; germinates well at 16°C soil temp and matures in 40–50 days before frost. Thin to 10 cm (4 in) spacing.
Arugula (Eruca sativa)
Direct-sow now for a 3–4 week harvest before frost; thrives in cool soil and tolerates light frosts. Sow every 10 days for succession.
Mâche (Valerianella locusta)
Cold-hardy salad green, sow now for October–November harvest. Germinates at cool temps and survives light frosts under mulch.
Radish (Raphanus sativus 'Cherry Belle' or 'Icicle')
Ready in 25–30 days; sow now for late-September harvest before soil gets waterlogged. Succession-sow for continuous crop.
Kale (Brassica oleracea 'Winterbor' or 'Lacinato')
Sow now for November–December harvest; flavor improves after frost. Germinates at 16°C in 7–10 days.
Start indoors now
Leeks (Allium porrum 'Bleu de Solaise')
Start seed indoors now; transplant out in 4–6 weeks for October planting. Harvest through winter in zone 5a.
Onions (Allium cepa 'Walla Walla' or storage types)
Start seed indoors for transplant in late October; long-day varieties suit your latitude and store well through winter.
Cabbage (Brassica oleracea 'January King' or 'Savoy')
Start seed indoors now for transplant in 4–5 weeks; these varieties store and improve in flavor after light frosts.
Harvest now
Tomatoes (all types)
Pick all fruit—ripe, turning, and green—before first frost (33 days away). Ripen indoors on a sunny windowsill or in a paper bag with an apple.
Peppers (Capsicum annuum)
Harvest all peppers now; they won't mature further outdoors. Green peppers are edible; red/yellow take longer than you have left.
Beans (Phaseolus vulgaris)
Pick all pods now; frost will kill plants within weeks. Dry mature pods for seed or shell beans.
Summer squash and zucchini (Cucurbita pepo)
Harvest regularly; plants decline rapidly as nights cool. Check daily for tender fruit; mature fruit becomes watery.
Tasks this week
- Clear spent tomato, pepper, and bean plants after harvest; compost disease-free material, burn or bin any blight-infected foliage.
- Mulch newly seeded beds with 2–3 cm (1 in) compost to retain moisture and moderate soil temp during rain and wind this week.
- Stake or trellis kale and other tall brassicas now; September winds (up to 29 km/h forecast) can topple young plants.
- Deadhead perennials and cut back spent annuals to redirect energy to root development before frost.
- Water deeply after heavy rain (29 mm forecast Sept 9); ensure good drainage to prevent root rot in cooling soil.
Watch out for
- Heavy rain and wind Sept 9–10 (29 km/h gusts): stake tall crops and ensure drainage; wet soil promotes fungal disease.
- Frost risk Sept 11 (low 7°C): tender annuals may be nipped; cover vulnerable seedlings if frost threatens.
- Powdery mildew and early blight thrive in cool, damp conditions—remove affected foliage and improve air circulation.
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