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When to Plant Crookneck Squash in Adams County, IA

Adams County, Iowa Zone 5b May

May in the garden — Adams County, Iowa

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost April 24
Avg. first frost October 11
Soil temp (4") 60°F
Watering Low
Pest pressure Low
Daylight 14.3 hrs
  1. Get crookneck squash in the ground

    Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.

  2. Plant crookneck squash from seed, right in the garden

    Thin ruthlessly once seedlings are up. Crowded roots mean smaller crops from every plant.

  3. Start crookneck squash indoors

    Your window is short. These crops want several weeks of indoor growth before they go outside.

Coming up in June — start thinking about
  • 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.

Adams County, Iowa is in USDA Zone 5b. The average last spring frost is April 24 and the first fall frost is October 11, giving you a growing season of approximately 170 days.

At an elevation of 998 feet, Adams County receives approximately 32.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Crookneck Squash during the growing season.

Adams County, IA (Zone 5b) Moderate season
170 days
Last Spring Frost April 24
170 growing days
First Fall Frost October 11

Adams County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (79 days to spare)
Start indoors: Mar 14 Transplant: May 2 🍅 Harvest: Jun 20 – Jul 18
Recommended (50%) ✓ Fits season (79 days to spare)
Start indoors: Mar 20 Transplant: May 8 🍅 Harvest: Jun 26 – Jul 24
Safe Start (90%) ✓ Fits season (78 days to spare)
Start indoors: Apr 3 Transplant: May 22 🍅 Harvest: Jul 10 – Aug 7

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 Adams County

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

Soil pH

Your soil pH (6.1–7.2) is within Crookneck Squash's preferred range (6.0–7.5).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.8%) — Crookneck Squash will thrive.

How to Plant Crookneck Squash

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

Succession Planting Crookneck Squash

4
successive plantings in your 170-day season

Sow every 5.1 weeks. Last sowing by Aug 12 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 376 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 1.4" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 4.3" 3.1" 1.2" 💧 Light watering
May 4.3" 4.3" 0" ✅ Rainfall sufficient
Jun 4.3" 3.8" 0.5" 💧 Light watering
Jul 4.3" 3.4" 0.9" 💧 Light watering
Aug 4.3" 3.2" 1.1" 💧 Light watering
Sep 4.3" 2.9" 1.4" 💧 Light watering
Oct 4.3" 2.6" 1.7" 💧 Light watering
Nov 2" 0" ❄️ Dormant
Dec 1.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Adams 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 ~761 GDD — county provides 2,465 GDD Excellent fit

Crookneck Squash Planting Timeline — Adams County, IA

Crookneck Squash Planting Calendar

Activity When Date Range
Start Indoors March 20 Mar 20 – Apr 3
Transplant Outdoors May 8 May 8 – May 22
Direct Sow May 1 May 1 – May 22
Harvest June 26 Jun 26 – Jul 24

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

Month-by-Month Timeline

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

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: ideal

🗺️ USDA Zone

Zone 5b

📆 Growing Season

170 days in Adams County

Growing Tips for Crookneck Squash in Adams County

Direct sow Crookneck Squash outdoors after April 24 in Adams County when soil has warmed and frost danger has passed.

Your generous 170.0-day season in Adams 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 Adams County, IA?

Adams County is in Zone 5b with an average last frost of April 24. Plan your Crookneck Squash planting based on this frost date — see the calendar above for exact timing.

What planting zone is Adams County, IA?

Adams County, Iowa is in USDA Hardiness Zone 5b. The average last spring frost is April 24 and first fall frost is October 11.

🌱

Your Adams County Garden Planner — Free

A 24-page printable planner built for Adams County (Zone 5b). 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 Adams County, IA. 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.