Regional guide

Upper Peninsula Michigan Short-Season Vegetable Garden

MSU Extension calendar guide for Upper Peninsula Michigan Zone 4b timing, local zone adjustments, soil temperature, and short-season frost ranges.

Climate signals

• MSU Extension's Upper Peninsula Michigan Gardening Calendar says its monthly planting dates are based on Zone 4b.
• The calendar says to plant 1 week earlier in Zone 5a, 2 weeks earlier in Zone 5b, and 1 week later in Zone 4a.
• The source says to always adjust based on local weather conditions and says soil temperature is more important than air temperature.
• Cool-season crops germinate best at 55 degrees F or warmer, while warm-season crops need 75 degrees F or warmer.

Planning notes

• Treat the calendar as an Upper Peninsula short-season guide, not as a Lower Peninsula base, Zone 6a base, or statewide Michigan planting date.
• 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 and harden off plants 7 to 10 days before transplanting outdoors.
• In May, Plant Seed Outdoors rows list Peas, Spinach, Lettuce, Carrots, Potatoes, Onion sets, and Radish; after frost rows list Broccoli, Cabbage, Cauliflower, Kale, Onions seedlings, and Leeks.
• In June, Plant rows list Zucchini, Pumpkins, Sweet corn, Beans, Tomatoes, Peppers, Eggplant, and Cucumbers.
• July fall crop rows list Radishes, Lettuce, Turnips, Spinach, and Kale; August fall crop rows list Spinach, Kale, Collards, and Beets.
• Average last spring frost ranges include Zone 4a June 1 to June 15 and Zone 4b May 25 to June 10; average first fall frost ranges include Zone 4a Sept. 5 to Sept. 20 and Zone 4b Sept. 10 to Sept. 25.
• Use these priority links as crop-level catalog examples for MSU Extension rows, not as potato, onion, garlic, zucchini, winter squash, cover crop, or exact cultivar recommendations.

Catalog crop examples

These catalog entries match crops covered by the regional timing source; variety-specific details remain tied to each seed entry's own source.

• American Flag Leek Vegetable · Cool · 120 days
• California Wonder Pepper Vegetable · Warm · 72 days
• Black Beauty Eggplant Vegetable · Warm · 80 days
• Waltham 29 Broccoli Vegetable · Cool · 74 days
• Golden Acre Cabbage Vegetable · Cool · 64 days
• Snowball Y Cauliflower Vegetable · Cool · 70 days
• Lacinato Kale Vegetable · Cool · 60 days
• Black Seeded Simpson Lettuce Vegetable · Cool · 45 days
• Roma Tomato Vegetable · Warm · 76 days
• Marketmore 76 Cucumber Vegetable · Warm · 58 days
• Sugar Snap Pea Vegetable · Cool · 62 days
• Bloomsdale Spinach Vegetable · Cool · 42 days
• Danvers 126 Carrot Vegetable · Shoulder · 70 days
• French Breakfast Radish Vegetable · Cool · 28 days
• Small Sugar Pumpkin Vegetable · Warm · 100 days
• Golden Bantam Sweet Corn Vegetable · Warm · 80 days
• Provider Bush Bean Vegetable · Warm · 50 days
• Purple Top White Globe Turnip Vegetable · Cool · 55 days
• Georgia Southern Collards Vegetable · Cool · 65 days
• Detroit Dark Red Beet Vegetable · Cool · 58 days

Related regional guides

• Lower Peninsula Michigan Garden Calendar MSU Extension Lower Peninsula calendar for Zone 6a timing, 5a-6b offsets, soil-temperature thresholds, fall crops, and frost ranges.

Source: MSU Extension Upper Peninsula Michigan Gardening Calendar