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When to Plant Collard Greens in Burnett County, WI

Burnett County, Wisconsin Zone 4a May

What to do in May

Your Burnett County, Wisconsin garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost May 15
Avg. first frost September 27
Soil temp (4") 50°F
Watering Moderate
Pest pressure Low
Daylight 14.7 hrs
  1. Time to transplant collard greens

    Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.

  2. Sow collard greens where they'll grow

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

Get ahead of June
  • 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.

Burnett County, Wisconsin is in USDA Zone 4a. The average last spring frost is May 15 and the first fall frost is September 27, giving you a growing season of approximately 135 days.

At an elevation of 574 feet, Burnett County receives approximately 30.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 79°F, so choose short-season varieties of Collard Greens to ensure they mature before fall.

Burnett County, WI (Zone 4a) Short season
135 days
Last Spring Frost May 15
135 growing days
First Fall Frost September 27
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Burnett County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (13 days to spare)
Start indoors: Mar 28 Transplant: May 9 🍅 Harvest: Jul 4 – Sep 5
Recommended (50%) ✓ Fits season (16 days to spare)
Start indoors: Apr 3 Transplant: May 15 🍅 Harvest: Jul 10 – Sep 11
Safe Start (90%) ✓ Fits season (13 days to spare)
Start indoors: Apr 18 Transplant: May 30 🍅 Harvest: Jul 25 – Sep 26

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 Burnett County

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

Soil pH

Your soil pH (6.2–7.3) overlaps with Collard Greens's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Collard Greens.

Organic Matter

Organic matter is excellent (4.6%) — Collard Greens will thrive.

How to Plant Collard Greens

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

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Succession Planting Collard Greens

2
successive plantings in your 135-day season

Sow every 6.3 weeks. Last sowing by Jul 14 to harvest before frost.

For a dedicated fall crop, sow by Jul 05.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
1.0″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 109 gal / 100 sq ft

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 1.4" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 1.8" 0" ❄️ Dormant
Apr 2.6" 0" ❄️ Dormant
May 3.5" 3.6" 0" ✅ Rainfall sufficient
Jun 3.5" 4.2" 0" ✅ Rainfall sufficient
Jul 3.5" 3" 0.5" 💧 Light watering
Aug 3.5" 3.6" 0" ✅ Rainfall sufficient
Sep 3.5" 2.7" 0.8" 💧 Light watering
Oct 2.5" 0" ❄️ Dormant
Nov 2" 0" ❄️ Dormant
Dec 1.7" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Burnett 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 ~601 GDD — county provides 1,248 GDD Excellent fit

Collard Greens Planting Timeline — Burnett County, WI

Collard Greens Planting Calendar

Activity When Date Range
Start Indoors April 3 Apr 3 – Apr 17
Transplant Outdoors May 15 May 15 – May 29
Direct Sow May 8 May 8 – May 29
Harvest July 10 Jul 10 – Sep 11
Fall Sowing July 5 Jul 5 – Jul 19

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 Harvest
September Harvest
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.8"/week · Only during dry spells

📅 Days to Maturity

55–75 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 4a

📆 Growing Season

135 days in Burnett County

Growing Tips for Collard Greens in Burnett County

Direct sow Collard Greens outdoors after May 15 in Burnett 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 Burnett County, WI?

Burnett County is in Zone 4a with an average last frost of May 15. Plan your Collard Greens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Burnett County, WI?

Burnett County, Wisconsin is in USDA Hardiness Zone 4a. The average last spring frost is May 15 and first fall frost is September 27.

🌱

Your Burnett County Garden Planner — Free

A 24-page printable planner built for Burnett County (Zone 4a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Burnett County, WI. 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.