When to Plant Collard Greens in Polk County, MN
May to-do list for Polk County, Minnesota
If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.
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Set out collard greens seedlings
Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.
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Direct-sow collard greens
Your soil is 48°F — warm enough for these to germinate without babying.
Coming up in June — start thinking about
- Starting indoors: collard greens
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.
Polk County, Minnesota is in USDA Zone 4a. The average last spring frost is May 11 and the first fall frost is October 1, giving you a growing season of approximately 143 days.
At an elevation of 1,053 feet, Polk County receives approximately 35.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 78°F, so choose short-season varieties of Collard Greens to ensure they mature before fall.
Polk County Soil Profile
Soil Type
Silt Loam
Soil pH
5.9-7.2
Drainage
Well Drained
Plant Planting Risk Windows
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 Polk County
How your county's soil matches Collard Greens's growing requirements.
Soil pH
Your soil pH (5.9–7.2) overlaps with Collard Greens's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Polk County is excellent for Collard Greens — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.2%) — Collard Greens will thrive.
How to Plant Collard Greens
Fall planting: Sow 12 weeks before your first frost date for a fall harvest.
Succession Planting Collard Greens
Sow every 6.3 weeks. Last sowing by Jul 18 to harvest before frost.
For a dedicated fall crop, sow by Jul 09.
Plant Water Budget
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 | — | 1.7" | 0" | ❄️ Dormant |
| Mar | — | 2.7" | 0" | ❄️ Dormant |
| Apr | — | 3.6" | 0" | ❄️ Dormant |
| May | 3.5" | 3.6" | 0" | ✅ Rainfall sufficient |
| Jun | 3.5" | 4.8" | 0" | ✅ Rainfall sufficient |
| Jul | 3.5" | 4.5" | 0" | ✅ Rainfall sufficient |
| Aug | 3.5" | 3.4" | 0.1" | 💧 Light watering |
| Sep | 3.5" | 2.9" | 0.6" | 💧 Light watering |
| Oct | 3.5" | 2.9" | 0.6" | 💧 Light watering |
| Nov | — | 2.3" | 0" | ❄️ Dormant |
| Dec | — | 1.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Polk 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 Planting Timeline — Polk County, MN
Collard Greens Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 30 | Mar 30 – Apr 13 |
| Transplant Outdoors | May 11 | May 11 – May 25 |
| Direct Sow | May 4 | May 4 – May 25 |
| Harvest | July 6 | Jul 6 – Sep 7 |
| Fall Sowing | July 9 | Jul 9 – Jul 23 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Fall Sowing Harvest |
| August | 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 4a
📆 Growing Season
143 days in Polk County
Growing Tips for Collard Greens in Polk County
Direct sow Collard Greens outdoors after May 11 in Polk 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
Check more plant combinations with our Companion Planting Checker →
Collard Greens in Other Locations
Frequently Asked Questions
When should I plant Collard Greens in Polk County, MN?
Polk County is in Zone 4a with an average last frost of May 11. Plan your Collard Greens planting based on this frost date — see the calendar above for exact timing.
What planting zone is Polk County, MN?
Polk County, Minnesota is in USDA Hardiness Zone 4a. The average last spring frost is May 11 and first fall frost is October 1.
Your Polk County Garden Planner — Free
A 24-page printable planner built for Polk 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.