Blog

When to Plant Cauliflower in Hamilton County, KS

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.

Hamilton County, Kansas is in USDA Zone 6a. The average last spring frost is April 27 and the first fall frost is October 12, giving you a growing season of approximately 168 days.

At an elevation of 871 feet, Hamilton County receives approximately 24 inches of rainfall annually with predominantly loam soil. Summer highs average 92ยฐF, providing good warmth for Cauliflower during the growing season.

Hamilton County, KS (Zone 6a) Moderate season
168 days
Last Spring Frost April 27
168 growing days
First Fall Frost October 12

Hamilton County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (50 days to spare)
Start indoors: Mar 17 Transplant: Apr 21 🍅 Harvest: Jun 16 – Aug 18
Recommended (50%) ✓ Fits season (49 days to spare)
Start indoors: Mar 23 Transplant: Apr 27 🍅 Harvest: Jun 22 – Aug 24
Safe Start (90%) ✓ Fits season (50 days to spare)
Start indoors: Apr 7 Transplant: May 12 🍅 Harvest: Jul 7 – Sep 8

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 Hamilton County

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

Soil pH

Your soil pH (6.3โ€“7.8) is more alkaline than Cauliflower prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Hamilton County is excellent for Cauliflower โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.3%) โ€” 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 168-day season

Sow every 6.3 weeks. Last sowing by Jul 04 to harvest before frost.

For a dedicated fall crop, sow by Aug 03.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 718 gal / 100 sq ft
Drought risk

Water stress score is 10/10 โ€” consider drought-tolerant varieties and mulching

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 โ€” 1.6" 0" โ„๏ธ Dormant
Feb โ€” 1.3" 0" โ„๏ธ Dormant
Mar โ€” 2.4" 0" โ„๏ธ Dormant
Apr 4.3" 2.8" 1.5" ๐Ÿ’ง Light watering
May 4.3" 3" 1.3" ๐Ÿ’ง Light watering
Jun 4.3" 1.5" 2.8" ๐Ÿšฟ Regular watering
Jul 4.3" 2.1" 2.2" ๐Ÿšฟ Regular watering
Aug 4.3" 2.6" 1.7" ๐Ÿ’ง Light watering
Sep 4.3" 1.7" 2.6" ๐Ÿšฟ Regular watering
Oct 4.3" 2" 2.3" ๐Ÿšฟ Regular watering
Nov โ€” 1.7" 0" โ„๏ธ Dormant
Dec โ€” 1.4" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Hamilton County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~1,472 GDD — county provides 3,192 GDD Excellent fit

Cauliflower Planting Timeline โ€” Hamilton County, KS

Cauliflower Planting Calendar

Activity When Date Range
Start Indoors March 23 Mar 23 โ€“ Apr 6
Transplant Outdoors April 27 Apr 27 โ€“ May 11
Direct Sow April 13 Apr 13 โ€“ May 4
Harvest June 22 Jun 22 โ€“ Aug 24
Fall Sowing August 3 Aug 3 โ€“ Aug 17

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

55โ€“100 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 6a

๐Ÿ“† Growing Season

168 days in Hamilton County

Growing Tips for Cauliflower in Hamilton County

Direct sow Cauliflower outdoors after April 27 in Hamilton County when soil has warmed and frost danger has passed.

Summer highs in Hamilton County reach 92ยฐF โ€” grow Cauliflower as a spring or fall crop. Use shade cloth if planting in summer.

Common pests for Cauliflower in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

Hamilton County receives only 24" of rain annually. Cauliflower needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

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 Hamilton County, KS?

Hamilton County is in Zone 6a with an average last frost of April 27. Plan your Cauliflower planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Hamilton County, KS?

Hamilton County, Kansas is in USDA Hardiness Zone 6a. The average last spring frost is April 27 and first fall frost is October 12.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Hamilton County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Hamilton County, KS. Local conditions may vary. Last updated: April 2026.