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When to Plant Collard Greens in Alcona County, MI

Alcona County, Michigan Zone 5b May

Alcona County, Michigan gardeners: here's your May plan

Welcome to May in Zone 5b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost May 17
Avg. first frost October 3
Soil temp (4") 57°F
Watering Low
Pest pressure Low
Daylight 14.6 hrs
  1. Move collard greens from tray to bed

    Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.

  2. Seed collard greens outdoors

    Rake a smooth bed, make a shallow furrow, drop seeds at the spacing on the packet, water gently, walk away.

To set up a strong June, finish these tasks
  • Starting indoors: collard greens

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Collard greens are a heat-tolerant member of the cabbage family with large, sturdy leaves. They are a Southern staple and one of the most nutritious leafy greens.

Alcona County, Michigan is in USDA Zone 5b. The average last spring frost is May 17 and the first fall frost is October 3, giving you a growing season of approximately 139 days.

At an elevation of 1,061 feet, Alcona County receives approximately 39 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Collard Greens during the growing season.

Alcona County, MI (Zone 5b) Short season
139 days
Last Spring Frost May 17
139 growing days
First Fall Frost October 3

Alcona County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (24 days to spare)
Start indoors: Apr 5 Transplant: May 10 🍅 Harvest: Jul 5 – Sep 6
Recommended (50%) ✓ Fits season (20 days to spare)
Start indoors: Apr 12 Transplant: May 17 🍅 Harvest: Jul 12 – Sep 13
Safe Start (90%) ✓ Fits season (26 days to spare)
Start indoors: Apr 23 Transplant: May 28 🍅 Harvest: Jul 23 – Sep 24

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Alcona County

How your county's soil matches Collard Greens's growing requirements.

Soil pH

Your soil pH (6.1–7.2) overlaps with Collard Greens's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Alcona County is excellent for Collard Greens — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.4%) — Collard Greens will thrive.

How to Plant Collard Greens

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Collard Greens

2
successive plantings in your 139-day season

Sow every 6.3 weeks. Last sowing by Jul 20 to harvest before frost.

For a dedicated fall crop, sow by Jul 25.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
1.2″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Collard Greens

Collard Greens needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.

Month Collard Greens Needs Rainfall You Supplement Action
Jan 1.7" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 3" 0" ❄️ Dormant
Apr 4" 0" ❄️ Dormant
May 3.5" 4" 0" ✅ Rainfall sufficient
Jun 3.5" 4.4" 0" ✅ Rainfall sufficient
Jul 3.5" 4.8" 0" ✅ Rainfall sufficient
Aug 3.5" 4.4" 0" ✅ Rainfall sufficient
Sep 3.5" 3.8" 0" ✅ Rainfall sufficient
Oct 3.5" 2.8" 0.7" 💧 Light watering
Nov 2.8" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Alcona County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Collard Greens Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Collard Greens needs ~942 GDD — county provides 2,015 GDD Excellent fit

Collard Greens Planting Timeline — Alcona County, MI

Collard Greens Planting Calendar

Activity When Date Range
Start Indoors April 12 Apr 12 – Apr 26
Transplant Outdoors May 17 May 17 – May 31
Direct Sow May 3 May 3 – May 24
Harvest July 12 Jul 12 – Sep 13
Fall Sowing July 25 Jul 25 – Aug 8

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May Transplant Outdoors Direct Sow
June
July Fall Sowing Harvest
August Fall Sowing Harvest
September Harvest
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.8"/week · Natural rainfall sufficient

📅 Days to Maturity

55–75 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 5b

📆 Growing Season

139 days in Alcona County

Growing Tips for Collard Greens in Alcona County

Direct sow Collard Greens outdoors after May 17 in Alcona County when soil has warmed and frost danger has passed.

Common pests for Collard Greens in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors or direct sow 4-6 weeks before last frost. Harvest lower leaves first, leaving the growing tip intact. Flavor improves after exposure to frost.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries
  • Tomatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Collard Greens in Alcona County, MI?

Alcona County is in Zone 5b with an average last frost of May 17. Plan your Collard Greens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Alcona County, MI?

Alcona County, Michigan is in USDA Hardiness Zone 5b. The average last spring frost is May 17 and first fall frost is October 3.

🌱

Your Alcona County Garden Planner — Free

A 24-page printable planner built for Alcona County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Alcona County, MI. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.