Michigan's Overlooked Season
Fall Gardening — Michigan's Secret Season
Most Michigan gardeners wind down in August, just as their gardens could be starting a second productive season. Fall is Michigan's most overlooked gardening opportunity — cooler temperatures reduce pest pressure, bring more rain, and create ideal growing conditions for an entirely different range of crops that failed in summer heat.
The math works: Zone 6a (Grand Rapids, Lansing) has on average 80+ frost-free days after August 1. Zone 6b (Detroit) has 90+ days. That's enough time for a full crop of broccoli, a succession of lettuce, several rounds of spinach, and a full kale harvest — all from beds vacated by summer crops.
Fall crops like kale and broccoli taste sweeter after a light frost — and produce heavily through October in Michigan.
Fall Planting Calendar
What to Plant August Through September
| Crop | Plant in Zone 6a–6b | Plant in Zone 5b | Days to Harvest | Flavor After Frost? |
|---|---|---|---|---|
| Spinach | Aug 15 – Sept 1 | Aug 5–20 | 40–50 | Yes — sweeter after frost |
| Lettuce (loose-leaf) | Aug 10 – Sept 5 | Aug 1–20 | 45–55 | Yes — milder and crisper |
| Kale | July 20 – Aug 15 | July 10 – Aug 1 | 55–65 | Yes — dramatically improved |
| Arugula | Aug 15 – Sept 10 | Aug 5–25 | 35–45 | Yes — less bitter after frost |
| Radishes | Aug 20 – Sept 15 | Aug 10 – Sept 1 | 25–30 | Minimal effect |
| Broccoli | Start indoors July 1, transplant Aug 1–10 | Start indoors June 20, transplant July 20–30 | 60–80 from transplant | Yes — sweeter heads |
| Cabbage (fall) | Start indoors July 1, transplant Aug 1–10 | Start indoors June 20, transplant July 20–30 | 70–90 from transplant | Yes — improved flavor |
| Turnips / Hakurei | Aug 10 – Sept 1 | Aug 1–20 | 38–50 | Yes — sweeter after frost |
| Beets | July 25 – Aug 15 | July 15 – Aug 1 | 55–70 | Yes — notably sweeter |
| Garlic (plant for next year) | Oct 1–20 | Sept 20 – Oct 10 | Harvests next July | Plant cloves in fall, harvest following summer |
Frost Extension
Keep Michigan's Fall Garden Going Longer
Row covers extend by 4–6 weeks
Lightweight row cover (Agribon AG-19) protects to about 28°F — extending your Michigan fall harvest through November in zone 6. Heavier Agribon AG-30 protects to 24°F. Combined with a cold frame, you can harvest spinach into December.
Cold frames: the game changer
A simple cold frame (wood box + old window) extends fall harvest 4–6 more weeks in Michigan. Zone 6b gardeners with a cold frame can harvest mâche, claytonia, and spinach all winter with little additional effort.
Mulch kale and root crops
Kale, Brussels sprouts, and parsnips in Michigan actually improve in flavor through multiple frosts. Apply 6 inches of straw mulch around root crops in October — they'll keep in the ground through November and beyond, acting as a natural root cellar.
More Michigan Gardening Resources
Seed Starting Guide
Planting Zones by City
Soil Testing 101
Last Frost Dates by City
Raised Beds for Clay Soil
Cool-Season Vegetables
When to Plant Tomatoes
Vegetable Planting Calendar
Eastern Market Detroit
Companion Planting Guide
Organic Pest Control
Best Herbs to Grow
Watering Your Garden
Succession Planting
Backyard Composting
Canning & Preserving
Native Plants for Pollinators
Winterizing Your Garden
Seed Saving Guide