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When to Plant Brussels Sprouts in Sargent County, ND

Sargent County, North Dakota Zone 4a May

This month in Sargent County, North Dakota

Here's what deserves your attention in Sargent County, North Dakota this month. Everything below is tailored to Zone 4a and timed around your local frost dates.

Avg. last frost May 8
Avg. first frost October 3
Soil temp (4") 54°F
Watering Low
Pest pressure Low
Daylight 14.8 hrs
  1. Move brussels sprouts from tray to bed

    Harden off for 7 days — a little more sun each day — before planting. That's the difference between a seedling that thrives and one that stalls.

  2. Seed brussels sprouts outdoors

    Your soil is 54°F — warm enough for these to germinate without babying.

To set up a strong June, finish these tasks
  • Starting indoors: brussels sprouts

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Brussels sprouts are a cold-hardy brassica that produces miniature cabbage-like heads along a tall stalk. Flavor improves after a light frost.

Sargent County, North Dakota is in USDA Zone 4a. The average last spring frost is May 8 and the first fall frost is October 3, giving you a growing season of approximately 148 days.

At an elevation of 733 feet, Sargent County receives approximately 34.1 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Brussels Sprouts to ensure they mature before fall.

Sargent County, ND (Zone 4a) Short season
148 days
Last Spring Frost May 8
148 growing days
First Fall Frost October 3

Sargent County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (6 days to spare)
Start indoors: Mar 17 Transplant: Apr 28 🍅 Harvest: Jul 28 – Sep 22
Recommended (50%) ✓ Fits season (1 days to spare)
Start indoors: Mar 27 Transplant: May 8 🍅 Harvest: Aug 7 – Oct 2
Safe Start (90%) ✓ Fits season (2 days to spare)
Start indoors: Apr 6 Transplant: May 18 🍅 Harvest: Aug 17 – Oct 12

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 Sargent County

How your county's soil matches Brussels Sprouts's growing requirements.

Soil pH

Your soil pH (6.5–7.2) is within Brussels Sprouts's preferred range (6.0–7.5).

Soil Texture

The loam soil in Sargent County is excellent for Brussels Sprouts — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.7%). Annual compost additions will help Brussels Sprouts.

How to Plant Brussels Sprouts

1"
Planting Depth
15"
Between Plants
24"
Between Rows

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

Plant Water Budget

Plant needs
0.9″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Brussels Sprouts

Brussels Sprouts needs approximately 0.9 inches of water per week (3.9" per month). Here's how your county's rainfall compares month by month.

Month Brussels Sprouts Needs Rainfall You Supplement Action
Jan 0.8" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 3.4" 0" ❄️ Dormant
May 3.9" 4.9" 0" ✅ Rainfall sufficient
Jun 3.9" 6" 0" ✅ Rainfall sufficient
Jul 3.9" 4" 0" ✅ Rainfall sufficient
Aug 3.9" 3.8" 0.1" 💧 Light watering
Sep 3.9" 3.6" 0.3" 💧 Light watering
Oct 3.9" 2.2" 1.7" 💧 Light watering
Nov 1.3" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Sargent County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Brussels Sprouts 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.

Brussels Sprouts needs ~1,182 GDD — county provides 1,591 GDD Excellent fit

Brussels Sprouts Planting Timeline — Sargent County, ND

Brussels Sprouts Planting Calendar

Activity When Date Range
Start Indoors March 27 Mar 27 – Apr 10
Transplant Outdoors May 8 May 8 – May 22
Direct Sow May 1 May 1 – May 22
Harvest August 7 Aug 7 – Oct 2
Fall Sowing July 11 Jul 11 – Jul 25

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors
May Transplant Outdoors Direct Sow
June
July Fall Sowing
August Harvest
September Harvest
October Harvest
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.9"/week · Natural rainfall sufficient

📅 Days to Maturity

90–130 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 4a

📆 Growing Season

148 days in Sargent County

Growing Tips for Brussels Sprouts in Sargent County

Direct sow Brussels Sprouts outdoors after May 08 in Sargent County when soil has warmed and frost danger has passed.

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

General growing tips

Start seeds indoors 12-14 weeks before first fall frost. Stake tall plants to prevent toppling. Remove lower leaves as sprouts develop to improve air circulation.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Brussels Sprouts in Sargent County, ND?

Sargent County is in Zone 4a with an average last frost of May 8. Plan your Brussels Sprouts planting based on this frost date — see the calendar above for exact timing.

What planting zone is Sargent County, ND?

Sargent County, North Dakota is in USDA Hardiness Zone 4a. The average last spring frost is May 8 and first fall frost is October 3.

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Your Sargent County Garden Planner — Free

A 24-page printable planner built for Sargent County (Zone 4a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Sargent County, ND. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.