When to plant Turnip in Mapleton, IA
Mapleton's climate puts the Turnip spring window between April 12 and May 3. time plantings around the expected last-frost window for best survival. A second sowing from August 1 to August 15 extends the harvest into fall.
When to Plant Turnip in Mapleton, IA
August in Monona County, Iowa — your action list
If you only do a handful of things in the garden this August, make it these. They're sequenced around your zone's frost timing.
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Start your fall crops: turnip
Fall crops get sweeter with a light frost. Don't be afraid of cool nights.
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.
Mapleton, Iowa is in USDA Zone 5a. The average last spring frost is April 26 and the first fall frost is October 10, giving you a growing season of approximately 167 days.
At an elevation of 732 feet, Monona County receives approximately 35.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Turnip to ensure they mature before fall.
Mapleton Soil Profile
Soil Type
Silt Loam
Soil pH
5.7-7.1
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 Mapleton
How your county's soil matches Turnip's growing requirements.
Soil pH
Your soil pH (5.7–7.1) overlaps with Turnip's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Monona County is excellent for Turnip — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Turnip.
Organic Matter
Organic matter is excellent (4.4%) — 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 11 to harvest before frost.
For a dedicated fall crop, sow by Aug 01.
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 | — | 1.7" | 0" | ❄️ Dormant |
| Mar | — | 2.8" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3" | 1.3" | 💧 Light watering |
| May | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| Jun | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4" | 0.3" | 💧 Light watering |
| Aug | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Sep | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| Oct | 4.3" | 3" | 1.3" | 💧 Light watering |
| Nov | — | 2.2" | 0" | ❄️ Dormant |
| Dec | — | 2.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Monona 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 — Mapleton, IA
Turnip Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | April 12 | Apr 12 – May 3 |
| Harvest | May 24 | May 24 – Jun 28 |
| Fall Sowing | August 1 | Aug 1 – Aug 15 |
Plant 0.5" deep · 4" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Direct Sow |
| May | Direct Sow Harvest |
| June | Harvest |
| July | — |
| August | Fall Sowing |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · 1-2 times/week
📅 Days to Maturity
40–60 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 5a
📆 Growing Season
167 days in Monona County
Growing Tips for Turnip in Mapleton
Direct sow Turnip outdoors after April 26 in Monona County when soil has warmed and frost danger has passed.
Your generous 167.0-day season in Monona 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
When should I plant Turnip in Mapleton, IA?
In Mapleton, IA, plant Turnip after the last frost (around April 26) and before the first frost (around October 10). Best results when soil holds above 50°F.
What growing zone is Mapleton, IA for Turnip?
Mapleton sits in USDA Zone 5a. Turnip grows reliably in zones 2a through 10b, so it's a good fit here.
Can Turnip grow in Mapleton's climate?
Yes — Turnip grows well in Mapleton's temperate climate. Mapleton averages a 167-day frost-free season, with last frost around April 26 and first frost around October 10.
Your Monona County Garden Planner — Free
A 22-page printable planner built for Monona County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.