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When to Plant Cauliflower in McNairy County, TN

McNairy County, Tennessee Zone 7b May

Your May gardening checklist

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in McNairy County, Tennessee.

Avg. last frost March 31
Avg. first frost October 28
Soil temp (4") 62°F
Watering Low
Pest pressure Moderate
Daylight 13.8 hrs
  1. Time to start cauliflower inside

    These need a head start before your last frost (March 31). Sow into cells now so you're ready to transplant in a few weeks.

  2. Start harvesting cauliflower

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

A few tasks this May that'll pay off in June
  • First harvests: cauliflower

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Cauliflower is a cool-season brassica that produces dense white, purple, or green heads called curds. It is more finicky than broccoli but rewards with a mild, nutty flavor.

McNairy County, Tennessee is in USDA Zone 7b. The average last spring frost is March 31 and the first fall frost is October 28, giving you a growing season of approximately 211 days.

At an elevation of 3,207 feet, McNairy County receives approximately 46 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Cauliflower during the growing season.

McNairy County, TN (Zone 7b) Long season
211 days
Last Spring Frost March 31
211 growing days
First Fall Frost October 28
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McNairy County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (95 days to spare)
Start indoors: Feb 17 Transplant: Mar 24 🍅 Harvest: May 19 – Jul 21
Recommended (50%) ✓ Fits season (92 days to spare)
Start indoors: Feb 24 Transplant: Mar 31 🍅 Harvest: May 26 – Jul 28
Safe Start (90%) ✓ Fits season (92 days to spare)
Start indoors: Mar 12 Transplant: Apr 16 🍅 Harvest: Jun 11 – Aug 13

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 McNairy County

How your county's soil matches Cauliflower's growing requirements.

Soil pH

Your soil pH (5.4–7.0) overlaps with Cauliflower's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Cauliflower.

How to Plant Cauliflower

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 Cauliflower

4
successive plantings in your 211-day season

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

For a dedicated fall crop, sow by Aug 19.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 158 gal / 100 sq ft

Monthly Watering Guide for Cauliflower

Cauliflower needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Cauliflower Needs Rainfall You Supplement Action
Jan 3.6" 0" ❄️ Dormant
Feb 4.1" 0" ❄️ Dormant
Mar 4.3" 4.3" 0" ✅ Rainfall sufficient
Apr 4.3" 3.2" 1.1" 💧 Light watering
May 4.3" 3.9" 0.4" 💧 Light watering
Jun 4.3" 4.2" 0.1" 💧 Light watering
Jul 4.3" 5" 0" ✅ Rainfall sufficient
Aug 4.3" 4.8" 0" ✅ Rainfall sufficient
Sep 4.3" 3.2" 1.1" 💧 Light watering
Oct 4.3" 3.1" 1.2" 💧 Light watering
Nov 3.2" 0" ❄️ Dormant
Dec 3.4" 0" ❄️ Dormant

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

Cauliflower 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.

Cauliflower needs ~1,298 GDD — county provides 3,534 GDD Excellent fit

Cauliflower Planting Timeline — McNairy County, TN

Cauliflower Planting Calendar

Activity When Date Range
Start Indoors February 24 Feb 24 – Mar 10
Transplant Outdoors March 31 Mar 31 – Apr 14
Direct Sow March 17 Mar 17 – Apr 7
Harvest May 26 May 26 – Jul 28
Fall Sowing August 19 Aug 19 – Sep 2

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

55–100 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

211 days in McNairy County

Growing Tips for Cauliflower in McNairy County

Direct sow Cauliflower outdoors after March 31 in McNairy County when soil has warmed and frost danger has passed.

Common pests for Cauliflower 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 6 weeks before transplanting. Blanch white varieties by tying outer leaves over the head. Provide consistent moisture and avoid temperature extremes.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cauliflower in McNairy County, TN?

McNairy County is in Zone 7b with an average last frost of March 31. Plan your Cauliflower planting based on this frost date — see the calendar above for exact timing.

What planting zone is McNairy County, TN?

McNairy County, Tennessee is in USDA Hardiness Zone 7b. The average last spring frost is March 31 and first fall frost is October 28.

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Your McNairy County Garden Planner — Free

A 24-page printable planner built for McNairy 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 McNairy 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.