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When to Plant Collard Greens in Polk County, TN

Polk County, Tennessee Zone 7b May

Top priorities for Polk County, Tennessee gardeners in May

A quick May briefing for Polk County, Tennessee gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 19
Avg. first frost October 19
Soil temp (4") 69°F
Watering Low
Pest pressure Moderate
Daylight 13.8 hrs
  1. Fire up the seed-starting tray: collard greens

    Label every cell. You will absolutely forget which is which otherwise.

To set up a strong June, finish these tasks
  • First harvests: 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.

Polk County, Tennessee is in USDA Zone 7b. The average last spring frost is April 19 and the first fall frost is October 19, giving you a growing season of approximately 183 days.

At an elevation of 1,255 feet, Polk County receives approximately 43.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Collard Greens during the growing season.

Polk County, TN (Zone 7b) Moderate season
183 days
Last Spring Frost April 19
183 growing days
First Fall Frost October 19
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Polk County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (70 days to spare)
Start indoors: Mar 6 Transplant: Apr 10 🍅 Harvest: Jun 5 – Aug 7
Recommended (50%) ✓ Fits season (64 days to spare)
Start indoors: Mar 15 Transplant: Apr 19 🍅 Harvest: Jun 14 – Aug 16
Safe Start (90%) ✓ Fits season (61 days to spare)
Start indoors: Mar 31 Transplant: May 5 🍅 Harvest: Jun 30 – Sep 1

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 (5.4–6.5) is more acidic than Collard Greens prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Polk 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 moderate (2.5%). Annual compost additions will help Collard Greens.

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

3
successive plantings in your 183-day season

Sow every 6.3 weeks. Last sowing by Aug 05 to harvest before frost.

For a dedicated fall crop, sow by Aug 10.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
1.0″/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 3.4" 0" ❄️ Dormant
Feb 3.8" 0" ❄️ Dormant
Mar 4.1" 0" ❄️ Dormant
Apr 3.5" 3.7" 0" ✅ Rainfall sufficient
May 3.5" 3.9" 0" ✅ Rainfall sufficient
Jun 3.5" 4.3" 0" ✅ Rainfall sufficient
Jul 3.5" 4" 0" ✅ Rainfall sufficient
Aug 3.5" 3.7" 0" ✅ Rainfall sufficient
Sep 3.5" 3.3" 0.2" 💧 Light watering
Oct 3.5" 2.6" 0.9" 💧 Light watering
Nov 2.9" 0" ❄️ Dormant
Dec 3.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–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 needs ~1,186 GDD — county provides 3,339 GDD Excellent fit

Collard Greens Planting Timeline — Polk County, TN

Collard Greens Planting Calendar

Activity When Date Range
Start Indoors March 15 Mar 15 – Mar 29
Transplant Outdoors April 19 Apr 19 – May 3
Direct Sow April 5 Apr 5 – Apr 26
Harvest June 14 Jun 14 – Aug 16
Fall Sowing August 10 Aug 10 – Aug 24

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 7b

📆 Growing Season

183 days in Polk County

Growing Tips for Collard Greens in Polk County

Direct sow Collard Greens outdoors after April 19 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

  • Strawberries
  • Tomatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Collard Greens in Polk County, TN?

Polk County is in Zone 7b with an average last frost of April 19. Plan your Collard Greens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Polk County, TN?

Polk County, Tennessee is in USDA Hardiness Zone 7b. The average last spring frost is April 19 and first fall frost is October 19.

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Your Polk County Garden Planner — Free

A 24-page printable planner built for Polk County (Zone 7b). 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 Polk County, TN. 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.