Now
21°C · Clear
Today
27° / 15°
Soil 6 cm
21°C
First frost
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Gardening in Boston
AI field guide · refreshed weeklyBoston Gardening: Early Fall Planting & Harvest (Sept 8–14)
Zone 6b with first frost Nov 2 (55 days away). Soil at 21°C (70°F) is still warm enough for cool-season crops to germinate and establish before winter. Spring frost Apr 19 means you have a full 197-day growing season. Plant now to harvest before hard freezes arrive in November.
Sow outdoors now
Spinach & Arugula
Direct sow now; both germinate fast in 21°C soil and tolerate light frosts. Harvest in 30–40 days (mid-October) before hard freeze.
Kale (Lacinato, Winterbor)
Sow now or transplant seedlings; these varieties sweeten after frost and produce through November. Sow direct or use 4-week-old transplants.
Mâche (Corn Salad)
Sow direct in rows; extremely cold-hardy and germinates in cool soil. Ready in 6–8 weeks, survives into December.
Radish (Cherry Belle, French Breakfast)
Quick crop (25 days); sow now for harvest by early October before soil cools further.
Turnip & Rutabaga
Sow now for root development before frost; turnips ready in 50–60 days, rutabagas in 80–90 days (late October–November harvest).
Start indoors now
Brassica Transplants (Cabbage, Broccoli)
Start seeds indoors now for 4–6 week old transplants; set out by late September for October harvest before hard freeze.
Garlic Cloves
Start in pots indoors now; transplant to garden in 3–4 weeks (early October) for October planting, or direct-plant cloves outdoors after Oct 15 for spring harvest.
Microgreens (Radish, Mustard, Broccoli)
Sow in shallow trays indoors; ready to harvest in 10–14 days. Extends fresh greens through winter on a sunny windowsill.
Harvest now
Tomatoes & Peppers
Pick all fruit now before first frost (Nov 2). Ripen green tomatoes indoors on a windowsill; peppers store 2–3 weeks in cool conditions.
Summer Squash & Zucchini
Harvest all mature fruit; plants slow as nights cool. Remove dead leaves to reduce powdery mildew.
Beans (Bush & Pole)
Pick regularly to encourage final flushes. Frost will kill plants within 6 weeks; pull and compost after last harvest.
Herbs (Basil, Cilantro, Parsley)
Cut basil before frost kills it; freeze or dry. Cilantro and parsley tolerate light frost; harvest before Nov 2.
Tasks this week
- Deadhead spent flowers and remove diseased foliage to reduce pest and disease pressure heading into fall.
- Water deeply after planting seeds or transplants; dry winds (15–25 km/h forecast) will stress new growth.
- Mulch newly sown beds with 2–3 cm (1 in) compost to retain moisture and moderate soil temperature swings.
- Scout for aphids, whiteflies, and powdery mildew on squash and brassicas; remove affected leaves or spray neem oil if needed.
- Prepare beds for garlic planting (mid-October) by incorporating compost and checking soil pH (garlic prefers 6.0–7.0).
Watch out for
- Powdery mildew thrives in cool, humid mornings; thin plants for airflow and avoid overhead watering.
- Cabbage moths and imported cabbageworms are active through fall—use row covers or Bt spray on brassicas.
- Soil temperature will drop 1–2°C per week; sow fast-maturing crops (radish, arugula) by Sept 20 for reliable germination.
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