When to Plant Brussels Sprouts in Coos County, OR
Your May game plan for Coos County, Oregon
Your garden in Coos County, Oregon is working on a schedule, even when you're not. Here's where you should be this May.
Get ahead of June
- First harvests: brussels sprouts
Brussels sprouts are a cold-hardy brassica that produces miniature cabbage-like heads along a tall stalk. Flavor improves after a light frost.
Coos County, Oregon is in USDA Zone 9a. The average last spring frost is March 22 and the first fall frost is November 19, giving you a growing season of approximately 242 days.
At an elevation of 96 feet, Coos County receives approximately 38.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Brussels Sprouts during the growing season.
Coos County Soil Profile
Soil Type
Silt Loam
Soil pH
5.4-6.8
Drainage
Well Drained
Plant 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 Coos County
How your county's soil matches Brussels Sprouts's growing requirements.
Soil pH
Your soil pH (5.4–6.8) overlaps with Brussels Sprouts's range (6.0–7.5), though not a perfect match.
Soil Texture
The silt loam soil in Coos County is excellent for Brussels Sprouts — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.7%) — Brussels Sprouts will thrive.
How to Plant Brussels Sprouts
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Plant Water Budget
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 | — | 5.5" | 0" | ❄️ Dormant |
| Feb | — | 4.5" | 0" | ❄️ Dormant |
| Mar | 3.9" | 4.4" | 0" | ✅ Rainfall sufficient |
| Apr | 3.9" | 3.1" | 0.8" | 💧 Light watering |
| May | 3.9" | 2.3" | 1.6" | 💧 Light watering |
| Jun | 3.9" | 1.6" | 2.3" | 🚿 Regular watering |
| Jul | 3.9" | 0.6" | 3.3" | 🚿 Regular watering |
| Aug | 3.9" | 0.8" | 3.1" | 🚿 Regular watering |
| Sep | 3.9" | 1.4" | 2.5" | 🚿 Regular watering |
| Oct | 3.9" | 3.3" | 0.6" | 💧 Light watering |
| Nov | 3.9" | 5.9" | 0" | ✅ Rainfall sufficient |
| Dec | — | 5.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Coos 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 Planting Timeline — Coos County, OR
Brussels Sprouts Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 22 | Feb 22 – Mar 8 |
| Transplant Outdoors | March 22 | Mar 22 – Apr 5 |
| Direct Sow | March 1 | Mar 1 – Mar 22 |
| Harvest | June 21 | Jun 21 – Aug 16 |
| Fall Sowing | September 24 | Sep 24 – Oct 8 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors Transplant Outdoors Direct Sow |
| April | Transplant Outdoors |
| May | — |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | Fall Sowing |
| October | Fall Sowing |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.9"/week · Only during dry spells
📅 Days to Maturity
90–130 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 9a
📆 Growing Season
242 days in Coos County
Growing Tips for Brussels Sprouts in Coos County
Direct sow Brussels Sprouts outdoors after March 22 in Coos 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
Check more plant combinations with our Companion Planting Checker →
Brussels Sprouts in Other Locations
Frequently Asked Questions
When should I plant Brussels Sprouts in Coos County, OR?
Coos County is in Zone 9a with an average last frost of March 22. Plan your Brussels Sprouts planting based on this frost date — see the calendar above for exact timing.
What planting zone is Coos County, OR?
Coos County, Oregon is in USDA Hardiness Zone 9a. The average last spring frost is March 22 and first fall frost is November 19.
Your Coos County Garden Planner — Free
A 24-page printable planner built for Coos County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.