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When to plant Green Beans in Knox County, IL

Plant Green Beans in Knox County after April 17; the prime window is April 24–May 15.

When to Plant Green Beans in Knox County, IL

Green Beans

Green beans are a warm-season staple available as bush or pole types. Bush beans produce a concentrated harvest while pole beans provide a longer picking season.

Knox County, Illinois is in USDA Zone 5b. The average last spring frost is April 17 and the first fall frost is October 15, giving you a growing season of approximately 181 days.

At an elevation of 1,301 feet, Knox County receives approximately 33.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Green Beans to ensure they mature before fall.

Knox County, IL (Zone 5b) Moderate season
181 days
Last Spring Frost April 17
181 growing days
First Fall Frost October 15

Knox County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Green Beans Planting Timeline — Knox County, IL

Green Beans Planting Calendar

Activity When Date Range
Direct Sow April 24 Apr 24 – May 15
Harvest June 19 Jun 19 – Aug 14

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

50–65 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 5b

📆 Growing Season

181 days in Knox County

Growing Tips for Knox County

Direct sow after last frost when soil is warm. Provide sturdy supports for pole varieties. Pick beans regularly when young and tender to encourage continued production.

Companion Planting

Good Companions

Avoid Planting Near

  • Onion
  • Garlic
  • Fennel

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Green Beans Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Allow pods to dry fully on vine until they rattle.
Storage Store airtight; viable 4 years at 35°F, under 45% humidity.

Avoid harvesting during damp weather. Isolate 25 ft between varieties.

Frequently Asked Questions

When should I plant Green Beans in Knox County, IL?

Knox County is in Zone 5b with an average last frost of April 17. Plan your Green Beans planting based on this frost date — see the calendar above for exact timing.

What planting zone is Knox County, IL?

Knox County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 17 and first fall frost is October 15.

When should I plant Green Beans in Knox County, IL?

In Knox County, IL, plant Green Beans after the last frost (around April 17) and before the first frost (around October 15). Best results when soil holds above 50°F.

What growing zone is Knox County, IL for Green Beans?

Knox County sits in USDA Zone 5b. Green Beans grows reliably in zones 3a through 11b, so it's a good fit here.

Can Green Beans grow in Knox County's climate?

Yes — Green Beans grows well in Knox County's temperate climate. Knox County averages a 181-day frost-free season, with last frost around April 17 and first frost around October 15.

🌱

Your Knox County Garden Planner — Free

A 22-page printable planner built for Knox 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.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Knox County, IL. Local conditions may vary. Last updated: July 2026.

Sources & credits

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