When to plant Turnip in Knox County, IL
Aim to plant Turnip in Knox County on or after April 3; the window stays open through April 24. Knox County's 181-day frost-free season gives you enough for a full main crop and a short fall succession. A second sowing from August 6 to August 20 extends the harvest into fall.
When to Plant Turnip in Knox County, IL
Your June gardening checklist
A quick June briefing for Knox County, Illinois gardeners — what's urgent, what's next, and what can wait.
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Start harvesting turnip
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
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.
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 Turnip to ensure they mature before fall.
Knox County Soil Profile
Soil Type
Silt Loam
Soil pH
6-6.8
Drainage
Well Drained
Turnip Planting Risk Windows
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 Knox County
How your county's soil matches Turnip's growing requirements.
Soil pH
Your soil pH (6.0–6.8) is within Turnip's preferred range (6.0–7.0).
Soil Texture
The silt loam soil in Knox County is excellent for Turnip — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.5%) — Turnip will thrive.
How to Plant Turnip
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Turnip
Sow every 4.6 weeks. Last sowing by Aug 16 to harvest before frost.
For a dedicated fall crop, sow by Aug 06.
Turnip Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Turnip
Turnip needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Turnip Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.4" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.4" | 0.9" | 💧 Light watering |
| May | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Jun | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Jul | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Aug | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Sep | 4.3" | 2.6" | 1.7" | 💧 Light watering |
| Oct | 4.3" | 2.7" | 1.6" | 💧 Light watering |
| Nov | — | 2.5" | 0" | ❄️ Dormant |
| Dec | — | 1.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Knox County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Turnip 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.
Turnip Planting Timeline — Knox County, IL
Turnip Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | April 3 | Apr 3 – Apr 24 |
| Harvest | May 15 | May 15 – Jun 19 |
| Fall Sowing | August 6 | Aug 6 – Aug 20 |
Plant 0.5" deep · 4" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Direct Sow |
| May | Harvest |
| June | Harvest |
| July | — |
| August | Fall Sowing |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Only during dry spells
📅 Days to Maturity
40–60 days
🧪 Soil pH
Needs 6–7 · Your soil: ideal
🗺️ USDA Zone
Zone 5b
📆 Growing Season
181 days in Knox County
Growing Tips for Turnip in Knox County
Direct sow Turnip outdoors after April 17 in Knox County when soil has warmed and frost danger has passed.
Your generous 181.0-day season in Knox County allows multiple plantings of Turnip. Sow every 20.0 days for continuous harvest.
Common pests for Turnip in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
General growing tips
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
Check more plant combinations with our Companion Planting Checker →
Turnip in Other Locations
Frequently Asked Questions
When should I plant Turnip in Knox County, IL?
Knox County is in Zone 5b with an average last frost of April 17. Plan your Turnip 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 Turnip in Knox County, IL?
In Knox County, IL, plant Turnip 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 Turnip?
Knox County sits in USDA Zone 5b. Turnip grows reliably in zones 2a through 10b, so it's a good fit here.
Can Turnip grow in Knox County's climate?
Yes — Turnip 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.