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When to Plant Turnip in Hamilton County, IL

Turnips are a fast-growing cool-season root vegetable with edible roots and greens. Baby turnips are sweet and tender while mature ones are more pungent.

Hamilton County, Illinois is in USDA Zone 6a. The average last spring frost is April 9 and the first fall frost is October 23, giving you a growing season of approximately 197 days.

At an elevation of 524 feet, Hamilton County receives approximately 39 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90ยฐF, providing good warmth for Turnip during the growing season.

Hamilton County, IL (Zone 6a) Moderate season
197 days
Last Spring Frost April 9
197 growing days
First Fall Frost October 23

Hamilton County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (120 days to spare)
Transplant: Apr 3 🍅 Harvest: May 15 – Jun 19
Recommended (50%) ✓ Fits season (120 days to spare)
Transplant: Apr 9 🍅 Harvest: May 21 – Jun 25
Safe Start (90%) ✓ Fits season (130 days to spare)
Transplant: Apr 20 🍅 Harvest: Jun 1 – Jul 6

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 355 gal / 100 sq ft
Drought risk

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

Turnip needs ~875 GDD — county provides 3,447 GDD Excellent fit

Turnip Planting Timeline โ€” Hamilton County, IL

Turnip Planting Calendar

Activity When Date Range
Direct Sow March 26 Mar 26 โ€“ Apr 16
Fall Sowing August 14 Aug 14 โ€“ Aug 28
Harvest May 7 May 7 โ€“ Jun 11

Plant 0.5" deep ยท 4" apart ยท Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

40โ€“60 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 6a

Growing Season

197 days

Growing Tips for Hamilton County

Direct sow in early spring or late summer. Harvest when roots are 2-3 inches in diameter for best flavor. Both the roots and the greens are nutritious and edible.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Level Up Your Garden

Frequently Asked Questions

When should I plant Turnip in Hamilton County, IL?

Hamilton County is in Zone 6a with an average last frost of April 9. Plan your Turnip planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Hamilton County, IL?

Hamilton County, Illinois is in USDA Hardiness Zone 6a. The average last spring frost is April 9 and first fall frost is October 23.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Hamilton County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.

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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 Hamilton County, IL. Local conditions may vary. Last updated: April 2026.