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When to Plant Turnip in Griggs County, ND

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.

Griggs County, North Dakota is in USDA Zone 4a. The average last spring frost is May 11 and the first fall frost is September 30, giving you a growing season of approximately 142 days.

At an elevation of 660 feet, Griggs County receives approximately 21.4 inches of rainfall annually with predominantly loam soil. Summer highs average 81ยฐF, so choose short-season varieties of Turnip to ensure they mature before fall.

Griggs County, ND (Zone 4a) Short season
142 days
Last Spring Frost May 11
142 growing days
First Fall Frost September 30

Griggs County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (67 days to spare)
Transplant: May 2 🍅 Harvest: Jun 13 – Jul 18
Recommended (50%) ✓ Fits season (65 days to spare)
Transplant: May 11 🍅 Harvest: Jun 22 – Jul 27
Safe Start (90%) ✓ Fits season (68 days to spare)
Transplant: May 22 🍅 Harvest: Jul 3 – Aug 7

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 Griggs County

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

Soil pH

Your soil pH (6.7โ€“7.8) is more alkaline than Turnip prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Griggs County is excellent for Turnip โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

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

How to Plant Turnip

0.5"
Planting Depth
4"
Between Plants
12"
Between Rows

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Succession Planting Turnip

4
successive plantings in your 142-day season

Sow every 4.6 weeks. Last sowing by Aug 01 to harvest before frost.

For a dedicated fall crop, sow by Jul 08.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 557 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” 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 โ€” 0.6" 0" โ„๏ธ Dormant
Feb โ€” 0.7" 0" โ„๏ธ Dormant
Mar โ€” 1.5" 0" โ„๏ธ Dormant
Apr โ€” 2.2" 0" โ„๏ธ Dormant
May 4.3" 3" 1.3" ๐Ÿ’ง Light watering
Jun 4.3" 3.5" 0.8" ๐Ÿ’ง Light watering
Jul 4.3" 2.7" 1.6" ๐Ÿ’ง Light watering
Aug 4.3" 2.4" 1.9" ๐Ÿ’ง Light watering
Sep 4.3" 2" 2.3" ๐Ÿšฟ Regular watering
Oct โ€” 1.4" 0" โ„๏ธ Dormant
Nov โ€” 0.7" 0" โ„๏ธ Dormant
Dec โ€” 0.6" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Sep in Griggs County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 needs ~538 GDD — county provides 1,526 GDD Excellent fit

Turnip Planting Timeline โ€” Griggs County, ND

Turnip Planting Calendar

Activity When Date Range
Direct Sow May 4 May 4 โ€“ May 25
Harvest June 15 Jun 15 โ€“ Jul 20
Fall Sowing July 8 Jul 8 โ€“ Jul 22

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

40โ€“60 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 4a

๐Ÿ“† Growing Season

142 days in Griggs County

Growing Tips for Turnip in Griggs County

Direct sow Turnip outdoors after May 11 in Griggs County when soil has warmed and frost danger has passed.

Common pests for Turnip in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

Griggs County receives only 21" of rain annually. Turnip needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

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

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Turnip in Griggs County, ND?

Griggs County is in Zone 4a with an average last frost of May 11. Plan your Turnip planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Griggs County, ND?

Griggs County, North Dakota is in USDA Hardiness Zone 4a. The average last spring frost is May 11 and first fall frost is September 30.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Griggs County gardeners in Zone 4a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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