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When to Plant Cauliflower in Richland County, WI

Richland County, Wisconsin Zone 5a May

What to do in May

Here's what deserves your attention in Richland County, Wisconsin this month. Everything below is tailored to Zone 5a and timed around your local frost dates.

Avg. last frost May 5
Avg. first frost October 5
Soil temp (4") 54°F
Watering Low
Pest pressure Low
Daylight 14.5 hrs
  1. Set out cauliflower seedlings

    Frost risk is low now in Richland County, Wisconsin. If you've been covering beds overnight, you can stop.

Looking ahead to June
  • Starting indoors: cauliflower
  • 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.

Richland County, Wisconsin is in USDA Zone 5a. The average last spring frost is May 5 and the first fall frost is October 5, giving you a growing season of approximately 153 days.

At an elevation of 1,098 feet, Richland County receives approximately 38.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Cauliflower during the growing season.

Richland County, WI (Zone 5a) Moderate season
153 days
Last Spring Frost May 5
153 growing days
First Fall Frost October 5
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Richland County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (34 days to spare)
Start indoors: Mar 25 Transplant: Apr 29 🍅 Harvest: Jun 24 – Aug 26
Recommended (50%) ✓ Fits season (34 days to spare)
Start indoors: Mar 31 Transplant: May 5 🍅 Harvest: Jun 30 – Sep 1
Safe Start (90%) ✓ Fits season (29 days to spare)
Start indoors: Apr 16 Transplant: May 21 🍅 Harvest: Jul 16 – Sep 17

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 Richland County

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

Soil pH

Your soil pH (5.8–6.9) overlaps with Cauliflower's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.9%) — Cauliflower will thrive.

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

3
successive plantings in your 153-day season

Sow every 6.3 weeks. Last sowing by Jun 27 to harvest before frost.

For a dedicated fall crop, sow by Jul 27.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 1.4" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 2.8" 0" ❄️ Dormant
Apr 3.8" 0" ❄️ Dormant
May 4.3" 4.1" 0.2" 💧 Light watering
Jun 4.3" 4.5" 0" ✅ Rainfall sufficient
Jul 4.3" 4.5" 0" ✅ Rainfall sufficient
Aug 4.3" 4.1" 0.2" 💧 Light watering
Sep 4.3" 3.6" 0.7" 💧 Light watering
Oct 4.3" 2.5" 1.8" 💧 Light watering
Nov 2.9" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Richland 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 ~1,066 GDD — county provides 2,103 GDD Excellent fit

Cauliflower Planting Timeline — Richland County, WI

Cauliflower Planting Calendar

Activity When Date Range
Start Indoors March 31 Mar 31 – Apr 14
Transplant Outdoors May 5 May 5 – May 19
Direct Sow April 21 Apr 21 – May 12
Harvest June 30 Jun 30 – Sep 1
Fall Sowing July 27 Jul 27 – Aug 10

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

55–100 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 5a

📆 Growing Season

153 days in Richland County

Growing Tips for Cauliflower in Richland County

Direct sow Cauliflower outdoors after May 05 in Richland 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 Richland County, WI?

Richland County is in Zone 5a with an average last frost of May 5. Plan your Cauliflower planting based on this frost date — see the calendar above for exact timing.

What planting zone is Richland County, WI?

Richland County, Wisconsin is in USDA Hardiness Zone 5a. The average last spring frost is May 5 and first fall frost is October 5.

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Your Richland County Garden Planner — Free

A 24-page printable planner built for Richland County (Zone 5a). 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 Richland 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.