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When to Plant Spinach in Jackson County, IL

Spinach is a nutrient-packed cool-season green that grows quickly in spring and fall. It is rich in iron, vitamins, and antioxidants and excellent raw or cooked.

Jackson County, Illinois is in USDA Zone 6b. The average last spring frost is April 10 and the first fall frost is October 21, giving you a growing season of approximately 194 days.

At an elevation of 1,046 feet, Jackson County receives approximately 38.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89ยฐF, providing good warmth for Spinach during the growing season.

Jackson County, IL (Zone 6b) Moderate season
194 days
Last Spring Frost April 10
194 growing days
First Fall Frost October 21

Jackson County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (94 days to spare)
Start indoors: Mar 1 Transplant: Apr 5 🍅 Harvest: May 10 – Jul 12
Recommended (50%) ✓ Fits season (96 days to spare)
Start indoors: Mar 6 Transplant: Apr 10 🍅 Harvest: May 15 – Jul 17
Safe Start (90%) ✓ Fits season (94 days to spare)
Start indoors: Mar 20 Transplant: Apr 24 🍅 Harvest: May 29 – Jul 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 Jackson County

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

Soil pH

Your soil pH (6.1โ€“7.1) overlaps with Spinach's range (6.5โ€“7.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Spinach.

Organic Matter

Organic matter is excellent (4.1%) โ€” Spinach will thrive.

How to Plant Spinach

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Spinach

6
successive plantings in your 194-day season

Sow every 4 weeks. Last sowing by Sep 01 to harvest before frost.

For a dedicated fall crop, sow by Aug 12.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.8″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 141 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Spinach

Spinach needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.

Month Spinach Needs Rainfall You Supplement Action
Jan โ€” 1.8" 0" โ„๏ธ Dormant
Feb โ€” 1.7" 0" โ„๏ธ Dormant
Mar โ€” 2.7" 0" โ„๏ธ Dormant
Apr 3" 3.4" 0" โœ… Rainfall sufficient
May 3" 4.1" 0" โœ… Rainfall sufficient
Jun 3" 5.8" 0" โœ… Rainfall sufficient
Jul 3" 4.3" 0" โœ… Rainfall sufficient
Aug 3" 3.9" 0" โœ… Rainfall sufficient
Sep 3" 3.7" 0" โœ… Rainfall sufficient
Oct 3" 2.9" 0.1" ๐Ÿ’ง Light watering
Nov โ€” 2.5" 0" โ„๏ธ Dormant
Dec โ€” 2.1" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Jackson County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Spinach 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.

Spinach needs ~712 GDD — county provides 3,249 GDD Excellent fit

Spinach Planting Timeline โ€” Jackson County, IL

Spinach Planting Calendar

Activity When Date Range
Start Indoors March 6 Mar 6 โ€“ Mar 20
Transplant Outdoors April 10 Apr 10 โ€“ Apr 24
Direct Sow March 27 Mar 27 โ€“ Apr 17
Harvest May 15 May 15 โ€“ Jul 17
Fall Sowing August 12 Aug 12 โ€“ Aug 26

Plant 0.5" deep ยท 6" apart ยท Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

0.7"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

35โ€“50 days

๐Ÿงช Soil pH

Needs 6.5โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 6b

๐Ÿ“† Growing Season

194 days in Jackson County

Growing Tips for Spinach in Jackson County

Direct sow Spinach outdoors after April 10 in Jackson County when soil has warmed and frost danger has passed.

Your generous 194.0-day season in Jackson County allows multiple plantings of Spinach. Sow every 17.0 days for continuous harvest.

General growing tips

Direct sow as soon as soil can be worked in spring. Plant in partial shade for summer crops to delay bolting. Succession plant every 2 weeks for continuous harvest.

Recommended Spinach Varieties for Jackson County

Slow-bolting spinach for warm springs โ€” best as fall crop here

Bloomsdale Long Standing Tyee Space

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

๐ŸŒพ Save Your Own Spinach Seeds
Life Cycle Annual
Pollination Wind Pollinated
How to Collect Let plants bolt. Harvest seed stalks when seeds turn tan.
Storage Store airtight; viable 5 years at 35ยฐF, under 45% humidity.

Wind pollinated โ€” isolate 1/2 mile for purity. Easy to let bolt in heat.

Frequently Asked Questions

When should I plant Spinach in Jackson County, IL?

Jackson County is in Zone 6b with an average last frost of April 10. Plan your Spinach planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Jackson County, IL?

Jackson County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 10 and first fall frost is October 21.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Jackson County gardeners in Zone 6b 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 Jackson County, IL. Local conditions may vary. Last updated: April 2026.