Upper Peninsula Michigan Gardening Calendar
DOWNLOADApril 1, 2026 - Melanie Fuhrmann
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EmailFor recommendations for the Lower Peninsula, see the Lower Peninsula Michigan Garden Calendar.
The following monthly planting dates are based on Zone 4b:
- Plant 1 week earlier in Zone 5a
- Plant 2 weeks earlier in Zone 5b
- Plant 1 week later in Zone 4a
(Always adjust based on local weather conditions.)
Soil temperature is more important than air temperature.
- Cool-season crops germinate best at 55°F+
- Warm-season crops need 75°F+
Warm soil speeds germination and reduces disease risk.
Most fall vegetables can be planted from July through early August in the Upper Peninsula. Check “days to maturity” and count backward from the first frost.
Cool-season crops tolerate light frost and often improve in flavor after a chill.
Start spring transplants indoors approximately 4 weeks before outdoor planting. Check the seed packet for exact timing. Harden off plants 7–10 days before transplanting outdoors.
Cool-season crops = leaves, stems, roots (lettuce, kale)
Warm-season crops = fruits (tomatoes, peppers, corn)
* = This list can be planted as seeds or transplants.
March
Plant (indoors):
- Onions
- Leeks
- Peppers
- Eggplant
Garden Tasks:
- Order seeds
- Create garden plan
- Start indoor seedlings for warm season crops
April
Plant (indoors):
- Broccoli
- Cabbage
- Cauliflower
- Kale
- Lettuce
- Tomatoes
- Cucumbers
- Zucchini
- Squash
Garden Tasks:
- Soil test as ground thaws
- Start indoor seedlings
May
Plant Seed Outdoors:
- Peas
- Spinach
- Lettuce
- Carrots
- Potatoes
- Onion sets
- Radish
After Frost*:
- Broccoli
- Cabbage
- Cauliflower
- Kale
- Onions (seedlings)
- Leeks
Garden Tasks:
- Harden off plants
- Thin early seedlings
June
Plant*:
- Zucchini
- Pumpkins
- Sweet corn
- Beans
- Tomatoes
- Peppers
- Eggplant
- Cucumbers
Garden Tasks:
- Weed and mulch
- Water regularly
- Scout pests
- Stake tomatoes and peas
July
Plant (Fall Crops):
- Radishes
- Lettuce
- Turnips
- Spinach
- Kale
Garden Tasks:
- Weed routinely
- Maintain irrigation
- Harvest often
- Fertilize if needed
- Monitor for pests and diseases
August
Plant (Fall Crops):
- Spinach
- Kale
- Collards
- Beets
Garden Tasks:
- Shade seedlings
- Continue harvest
- Remove spent plants
- Monitor for pests and diseases
September
Plant:
- Garlic
- Cover crops
Garden Tasks:
- Remove old plants
- Watch for first frost
October
Garden Tasks:
- Harvest remaining crops
- Clean beds
- Amend soil with organic matter
- Mulch garlic
November
Garden Tasks:
- Soil test (if ground isn't frozen)
- Mulch garden
- Clean and store tools
- Review season
- Plan next year’s garden
Average Last Spring Frost
Zone 4a: June 1 - June 15
Zone 4b: May 25 - June 10
Zone 5a: May 20 - May 30
Zone 5b: May 10 - May 25
Zone 6a: May 1 - May 15
Zone 6b: April 15 - April 30
Average First Fall Frost
Zone 4a: Sept. 5 - Sept. 20
Zone 4b: Sept. 10 - Sept. 25
Zone 5a: Sept. 20 - Oct. 1
Zone 5b: Sept. 25 - Oct. 10
Zone 6a: Oct. 6 - Oct. 21
Zone 6b: Oct. 15 - Oct. 31
*These are approximate ranges for most years across each zone*
Michigan Plant Hardiness Zone Map
