Blog

When to Plant Brussels Sprouts in Adair County, MO

Adair County, Missouri Zone 6a May

May in Adair County, Missouri — your action list

Welcome to May in Zone 6a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 17
Avg. first frost October 17
Soil temp (4") 56°F
Watering Moderate
Pest pressure Low
Daylight 14.2 hrs
  1. Sow brussels sprouts in trays indoors

    Your window is short. These crops want several weeks of indoor growth before they go outside.

Instant PDF download. No spam, unsubscribe any time.

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

Adair County, Missouri is in USDA Zone 6a. The average last spring frost is April 17 and the first fall frost is October 17, giving you a growing season of approximately 183 days.

At an elevation of 1,327 feet, Adair County receives approximately 34.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Brussels Sprouts during the growing season.

Adair County, MO (Zone 6a) Moderate season
183 days
Last Spring Frost April 17
183 growing days
First Fall Frost October 17
Share this guide:

Adair 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 (36 days to spare)
Start indoors: Mar 7 Transplant: Apr 11 🍅 Harvest: Jul 11 – Sep 5
Recommended (50%) ✓ Fits season (36 days to spare)
Start indoors: Mar 13 Transplant: Apr 17 🍅 Harvest: Jul 17 – Sep 11
Safe Start (90%) ✓ Fits season (34 days to spare)
Start indoors: Mar 29 Transplant: May 3 🍅 Harvest: Aug 2 – Sep 27

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 Adair County

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

Soil pH

Your soil pH (5.8–6.7) overlaps with Brussels Sprouts's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Brussels Sprouts.

Organic Matter

Organic matter is moderate (3.0%). Annual compost additions will help Brussels Sprouts.

How to Plant Brussels Sprouts

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

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
0.9″/week
Rainfall provides
0.8″/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 1.7" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 3.9" 3.8" 0.1" 💧 Light watering
May 3.9" 3.6" 0.3" 💧 Light watering
Jun 3.9" 4.2" 0" ✅ Rainfall sufficient
Jul 3.9" 3.5" 0.4" 💧 Light watering
Aug 3.9" 4.1" 0" ✅ Rainfall sufficient
Sep 3.9" 2.9" 1" 💧 Light watering
Oct 3.9" 2.8" 1.1" 💧 Light watering
Nov 2.3" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Adair 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 ~1,595 GDD — county provides 2,653 GDD Excellent fit

Brussels Sprouts Planting Timeline — Adair County, MO

Brussels Sprouts Planting Calendar

Activity When Date Range
Start Indoors March 13 Mar 13 – Mar 27
Transplant Outdoors April 17 Apr 17 – May 1
Direct Sow April 3 Apr 3 – Apr 24
Harvest July 17 Jul 17 – Sep 11
Fall Sowing August 8 Aug 8 – Aug 22

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

Month-by-Month Timeline

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

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: acceptable

🗺️ USDA Zone

Zone 6a

📆 Growing Season

183 days in Adair County

Growing Tips for Brussels Sprouts in Adair County

Direct sow Brussels Sprouts outdoors after April 17 in Adair 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 Adair County, MO?

Adair County is in Zone 6a with an average last frost of April 17. Plan your Brussels Sprouts planting based on this frost date — see the calendar above for exact timing.

What planting zone is Adair County, MO?

Adair County, Missouri is in USDA Hardiness Zone 6a. The average last spring frost is April 17 and first fall frost is October 17.

🌱

Your Adair County Garden Planner — Free

A 24-page printable planner built for Adair County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Adair County, MO. 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.