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When to Plant Crookneck Squash in St. Charles County, MO

St. Charles County, Missouri Zone 6b May

This month in St. Charles County, Missouri

Each item below is timed to St. Charles County, Missouri's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 13
Avg. first frost October 24
Soil temp (4") 61°F
Watering Moderate
Pest pressure Low
Daylight 14.1 hrs
  1. Start crookneck squash indoors

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

Get ahead of June
  • First harvests: crookneck squash

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Yellow crookneck squash is a summer squash with a curved neck and bumpy, bright yellow skin. It has a buttery flavor and is best harvested young when 4-6 inches long.

St. Charles County, Missouri is in USDA Zone 6b. The average last spring frost is April 13 and the first fall frost is October 24, giving you a growing season of approximately 194 days.

At an elevation of 1,295 feet, St. Charles County receives approximately 33.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Crookneck Squash during the growing season.

St. Charles County, MO (Zone 6b) Moderate season
194 days
Last Spring Frost April 13
194 growing days
First Fall Frost October 24
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St. Charles County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (103 days to spare)
Start indoors: Mar 2 Transplant: Apr 20 🍅 Harvest: Jun 8 – Jul 6
Recommended (50%) ✓ Fits season (103 days to spare)
Start indoors: Mar 9 Transplant: Apr 27 🍅 Harvest: Jun 15 – Jul 13
Safe Start (90%) ✓ Fits season (102 days to spare)
Start indoors: Mar 22 Transplant: May 10 🍅 Harvest: Jun 28 – Jul 26

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 St. Charles County

How your county's soil matches Crookneck Squash's growing requirements.

Soil pH

Your soil pH (5.7–6.6) overlaps with Crookneck Squash's range (6.0–7.5), though not a perfect match.

Soil Texture

The silt loam soil in St. Charles County is excellent for Crookneck Squash — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.1%). Annual compost additions will help Crookneck Squash.

How to Plant Crookneck Squash

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Succession Planting Crookneck Squash

5
successive plantings in your 194-day season

Sow every 5.1 weeks. Last sowing by Aug 25 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 471 gal / 100 sq ft

Monthly Watering Guide for Crookneck Squash

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

Month Crookneck Squash Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 4.3" 3" 1.3" 💧 Light watering
May 4.3" 3.6" 0.7" 💧 Light watering
Jun 4.3" 4.8" 0" ✅ Rainfall sufficient
Jul 4.3" 4.1" 0.2" 💧 Light watering
Aug 4.3" 3.6" 0.7" 💧 Light watering
Sep 4.3" 2.6" 1.7" 💧 Light watering
Oct 4.3" 2.4" 1.9" 💧 Light watering
Nov 2.1" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

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

Crookneck Squash 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.

Crookneck Squash needs ~801 GDD — county provides 2,958 GDD Excellent fit

Crookneck Squash Planting Timeline — St. Charles County, MO

Crookneck Squash Planting Calendar

Activity When Date Range
Start Indoors March 9 Mar 9 – Mar 23
Transplant Outdoors April 27 Apr 27 – May 11
Direct Sow April 20 Apr 20 – May 11
Harvest June 15 Jun 15 – Jul 13

Plant 1" deep · 30" apart · Rows 42" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June Harvest
July Harvest
August
September
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

45–60 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

194 days in St. Charles County

Growing Tips for Crookneck Squash in St. Charles County

Direct sow Crookneck Squash outdoors after April 13 in St. Charles County when soil has warmed and frost danger has passed.

Your generous 194.0-day season in St. Charles County allows multiple plantings of Crookneck Squash. Sow every 22.0 days for continuous harvest.

Common pests for Crookneck Squash in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow after last frost on mounds. Pick frequently while small for tender texture. Skin becomes tough and warty on larger fruits. Very productive in warm weather.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Crookneck Squash in St. Charles County, MO?

St. Charles County is in Zone 6b with an average last frost of April 13. Plan your Crookneck Squash planting based on this frost date — see the calendar above for exact timing.

What planting zone is St. Charles County, MO?

St. Charles County, Missouri is in USDA Hardiness Zone 6b. The average last spring frost is April 13 and first fall frost is October 24.

🌱

Your St. Charles County Garden Planner — Free

A 24-page printable planner built for St. Charles County (Zone 6b). 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 St. Charles County, MO. 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.