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When to Plant Squash (Summer) in Jefferson County, KS

Jefferson County, Kansas Zone 6b May

Your May planting checklist for Jefferson County, Kansas

A quick May briefing for Jefferson County, Kansas gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 14
Avg. first frost October 24
Soil temp (4") 62°F
Watering Moderate
Pest pressure Low
Daylight 14.2 hrs
  1. Sow squash (summer) in trays indoors

    You're about 24 weeks out from your last frost — the perfect window to get these germinating indoors.

To set up a strong June, finish these tasks
  • First harvests: squash (summer)

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Summer squash includes zucchini, yellow crookneck, and pattypan varieties that are harvested young and tender. They are prolific producers in warm weather.

Jefferson County, Kansas is in USDA Zone 6b. The average last spring frost is April 14 and the first fall frost is October 24, giving you a growing season of approximately 193 days.

At an elevation of 559 feet, Jefferson County receives approximately 23.8 inches of rainfall annually with predominantly loam soil. Summer highs average 90°F, providing good warmth for Squash (Summer) during the growing season.

Jefferson County, KS (Zone 6b) Moderate season
193 days
Last Spring Frost April 14
193 growing days
First Fall Frost October 24
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Jefferson County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (66 days to spare)
Start indoors: Mar 3 Transplant: Apr 21 🍅 Harvest: Jun 9 – Aug 11
Recommended (50%) ✓ Fits season (67 days to spare)
Start indoors: Mar 10 Transplant: Apr 28 🍅 Harvest: Jun 16 – Aug 18
Safe Start (90%) ✓ Fits season (69 days to spare)
Start indoors: Mar 23 Transplant: May 11 🍅 Harvest: Jun 29 – Aug 31

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 Jefferson County

How your county's soil matches Squash (Summer)'s growing requirements.

Soil pH

Your soil pH (6.7–7.6) overlaps with Squash (Summer)'s range (6.0–7.5), though not a perfect match.

Soil Texture

The loam soil in Jefferson County is excellent for Squash (Summer) — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.3%). Annual compost additions will help Squash (Summer).

How to Plant Squash (Summer)

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

Succession Planting Squash (Summer)

5
successive plantings in your 193-day season

Sow every 5.1 weeks. Last sowing by Aug 20 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.5″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 994 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Squash (Summer)

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

Month Squash (Summer) Needs Rainfall You Supplement Action
Jan 0.7" 0" ❄️ Dormant
Feb 0.7" 0" ❄️ Dormant
Mar 1.4" 0" ❄️ Dormant
Apr 4.3" 2.5" 1.8" 💧 Light watering
May 4.3" 3.3" 1" 💧 Light watering
Jun 4.3" 3.5" 0.8" 💧 Light watering
Jul 4.3" 3.5" 0.8" 💧 Light watering
Aug 4.3" 2.6" 1.7" 💧 Light watering
Sep 4.3" 2.5" 1.8" 💧 Light watering
Oct 4.3" 1.4" 2.9" 🚿 Regular watering
Nov 0.8" 0" ❄️ Dormant
Dec 0.7" 0" ❄️ Dormant

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

Squash (Summer) 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.

Squash (Summer) needs ~962 GDD — county provides 3,377 GDD Excellent fit

Squash (Summer) Planting Timeline — Jefferson County, KS

Squash (Summer) Planting Calendar

Activity When Date Range
Start Indoors March 10 Mar 10 – Mar 24
Transplant Outdoors April 28 Apr 28 – May 12
Direct Sow April 21 Apr 21 – May 12
Harvest June 16 Jun 16 – Aug 18

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 Harvest
September
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

45–65 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

193 days in Jefferson County

Growing Tips for Squash (Summer) in Jefferson County

Direct sow Squash (Summer) outdoors after April 14 in Jefferson County when soil has warmed and frost danger has passed.

Your generous 193.0-day season in Jefferson County allows multiple plantings of Squash (Summer). Sow every 22.0 days for continuous harvest.

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

Jefferson County receives only 24" of rain annually. Squash (Summer) needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow after last frost on mounds. Harvest frequently when fruits are 6-8 inches for best texture. Check plants daily as they grow rapidly in summer heat.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Squash (Summer) in Jefferson County, KS?

Jefferson County is in Zone 6b with an average last frost of April 14. Plan your Squash (Summer) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Jefferson County, KS?

Jefferson County, Kansas is in USDA Hardiness Zone 6b. The average last spring frost is April 14 and first fall frost is October 24.

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Your Jefferson County Garden Planner — Free

A 24-page printable planner built for Jefferson 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 Jefferson County, KS. 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.