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When to Plant Romanesco in Polk County, TN

Polk County, Tennessee Zone 7b May

Your May gardening checklist

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

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. Indoor seed-starting week for romanesco

    A seed-starting mix and a sunny window (or a grow light) are all you need. Keep soil warm — around 70°F — for fast germination.

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Romanesco is a stunning brassica with a lime-green head composed of fractal-patterned spiraling florets. It has a nuttier, milder flavor than cauliflower.

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 Romanesco 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

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 26 – Aug 7
Recommended (50%) ✓ Fits season (64 days to spare)
Start indoors: Mar 15 Transplant: Apr 19 🍅 Harvest: Jul 5 – Aug 16
Safe Start (90%) ✓ Fits season (61 days to spare)
Start indoors: Mar 31 Transplant: May 5 🍅 Harvest: Jul 21 – 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 Romanesco's growing requirements.

Soil pH

Your soil pH (5.4–6.5) is more acidic than Romanesco prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Romanesco.

Organic Matter

Organic matter is moderate (2.5%). Annual compost additions will help Romanesco.

How to Plant Romanesco

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 Romanesco

2
successive plantings in your 183-day season

Sow every 8.6 weeks. Last sowing by Jul 11 to harvest before frost.

For a dedicated fall crop, sow by Aug 10.

Plant Water Budget

Plant needs
1.0″/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 Romanesco

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

Month Romanesco Needs Rainfall You Supplement Action
Jan 3.4" 0" ❄️ Dormant
Feb 3.8" 0" ❄️ Dormant
Mar 4.1" 0" ❄️ Dormant
Apr 4.3" 3.7" 0.6" 💧 Light watering
May 4.3" 3.9" 0.4" 💧 Light watering
Jun 4.3" 4.3" 0" ✅ Rainfall sufficient
Jul 4.3" 4" 0.3" 💧 Light watering
Aug 4.3" 3.7" 0.6" 💧 Light watering
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 2.6" 1.7" 💧 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.

Romanesco 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.

Romanesco needs ~1,597 GDD — county provides 3,339 GDD Excellent fit

Romanesco Planting Timeline — Polk County, TN

Romanesco 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 July 5 Jul 5 – 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
July Harvest
August Fall Sowing Harvest
September
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

75–100 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 7b

📆 Growing Season

183 days in Polk County

Growing Tips for Romanesco in Polk County

Direct sow Romanesco outdoors after April 19 in Polk County when soil has warmed and frost danger has passed.

Common pests for Romanesco 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 5-7 weeks before transplanting. Provide consistent moisture and avoid temperature stress. Harvest when head is fully formed but before florets begin to separate.

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 Romanesco in Polk County, TN?

Polk County is in Zone 7b with an average last frost of April 19. Plan your Romanesco 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.

🌱

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.