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When to plant Spinach in Boone County County,

Spinach planted in Boone County County between April 9 and April 30 matures in 50 days — well before the October 16 first frost. A second sowing from August 7 to August 21 extends the harvest into fall.

When to Plant Spinach in Boone County, IL

Spinach
Boone County, Illinois Zone 5b June

June to-do list for Boone County, Illinois

Your garden in Boone County, Illinois is working on a schedule, even when you're not. Here's where you should be this June.

Avg. last frost April 23
Avg. first frost October 16
Soil temp (4") 71°F
Watering Low
Pest pressure High
Daylight 15.1 hrs
  1. It's harvest week for spinach

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

July will be here before you know it — start on
  • First harvests: spinach

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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.

Boone County, Illinois is in USDA Zone 5b. The average last spring frost is April 23 and the first fall frost is October 16, giving you a growing season of approximately 176 days.

At an elevation of 512 feet, Boone County receives approximately 39.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Spinach to ensure they mature before fall.

Boone County, IL (Zone 5b) Moderate season
176 days
Last Spring Frost April 23
176 growing days
First Fall Frost October 16

Boone County Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.8

Drainage

Well Drained

Spinach Planting Risk Windows

Early Start (70% safe) ✓ Fits season (79 days to spare)
Start indoors: Mar 13 Transplant: Apr 17 🍅 Harvest: May 22 – Jul 24
Recommended (50%) ✓ Fits season (78 days to spare)
Start indoors: Mar 19 Transplant: Apr 23 🍅 Harvest: May 28 – Jul 30
Safe Start (90%) ✓ Fits season (75 days to spare)
Start indoors: Apr 5 Transplant: May 10 🍅 Harvest: Jun 14 – Aug 16

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 Boone County

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

Soil pH

Your soil pH (6.0–6.8) is more acidic than Spinach prefers (6.5–7.5). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Spinach.

Organic Matter

Organic matter is moderate (3.8%). Annual compost additions will help Spinach.

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 176-day season

Sow every 4 weeks. Last sowing by Aug 27 to harvest before frost.

For a dedicated fall crop, sow by Aug 07.

Spinach Water Budget

Plant needs
0.7″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 1.6" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 3" 3.4" 0" ✅ Rainfall sufficient
May 3" 4.1" 0" ✅ Rainfall sufficient
Jun 3" 5.7" 0" ✅ Rainfall sufficient
Jul 3" 4.9" 0" ✅ Rainfall sufficient
Aug 3" 3.8" 0" ✅ Rainfall sufficient
Sep 3" 3.5" 0" ✅ Rainfall sufficient
Oct 3" 3.5" 0" ✅ Rainfall sufficient
Nov 2.9" 0" ❄️ Dormant
Dec 2.3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Boone County). Supplement amounts are based on average rainfall — 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" — 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.

Spinach needs ~521 GDD — county provides 2,156 GDD Excellent fit

Spinach Planting Timeline — Boone County, IL

Spinach Planting Calendar

Activity When Date Range
Start Indoors March 19 Mar 19 – Apr 2
Transplant Outdoors April 23 Apr 23 – May 7
Direct Sow April 9 Apr 9 – Apr 30
Harvest May 28 May 28 – Jul 30
Fall Sowing August 7 Aug 7 – Aug 21

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.7"/week · Natural rainfall sufficient

📅 Days to Maturity

35–50 days

🧪 Soil pH

Needs 6.5–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 5b

📆 Growing Season

176 days in Boone County

Growing Tips for Spinach in Boone County

Direct sow Spinach outdoors after April 23 in Boone County when soil has warmed and frost danger has passed.

Your generous 176.0-day season in Boone 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.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

🌾 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 35°F, under 45% humidity.

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

Frequently Asked Questions

When should I plant Spinach in Boone County, IL?

Boone County is in Zone 5b with an average last frost of April 23. Plan your Spinach planting based on this frost date — see the calendar above for exact timing.

What planting zone is Boone County, IL?

Boone County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 23 and first fall frost is October 16.

When should I plant Spinach in Boone County, ?

In Boone County, , plant Spinach after the last frost (around April 23) and before the first frost (around October 16). Best results when soil holds above 50°F.

What growing zone is Boone County, for Spinach?

Boone County sits in USDA Zone 5b. Spinach grows reliably in zones 2a through 10b, so it's a good fit here.

Can Spinach grow in Boone County's climate?

Yes — Spinach grows well in Boone County's temperate climate. Boone County averages a 176-day frost-free season, with last frost around April 23 and first frost around October 16.

🌱

Your Boone County Garden Planner — Free

A 22-page printable planner built for Boone 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 Boone County, IL. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.