When to Plant Basil in Coos County, OR
What to do in May
Your garden in Coos County, Oregon is working on a schedule, even when you're not. Here's where you should be this May.
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Get basil seeds going inside
Starting these indoors now means sturdy transplants ready the moment your soil warms up.
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Bring in the basil
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
June prep starts now
- First harvests: basil
Basil is a fragrant warm-season herb essential to Italian and Thai cuisines. It comes in many varieties including sweet, Thai, purple, and lemon types.
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 Basil 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 Basil's growing requirements.
Soil pH
Your soil pH (5.4–6.8) overlaps with Basil's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Coos County is excellent for Basil — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.7%) — Basil will thrive.
How to Plant Basil
Succession Planting Basil
Sow every 5.7 weeks. Last sowing by Sep 05 to harvest before frost.
Plant Water Budget
Monthly Watering Guide for Basil
Basil needs approximately 0.6 inches of water per week (2.6" per month). Here's how your county's rainfall compares month by month.
| Month | Basil Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 5.5" | 0" | ❄️ Dormant |
| Feb | — | 4.5" | 0" | ❄️ Dormant |
| Mar | 2.6" | 4.4" | 0" | ✅ Rainfall sufficient |
| Apr | 2.6" | 3.1" | 0" | ✅ Rainfall sufficient |
| May | 2.6" | 2.3" | 0.3" | 💧 Light watering |
| Jun | 2.6" | 1.6" | 1" | 💧 Light watering |
| Jul | 2.6" | 0.6" | 2" | 🚿 Regular watering |
| Aug | 2.6" | 0.8" | 1.8" | 🚿 Regular watering |
| Sep | 2.6" | 1.4" | 1.2" | 💧 Light watering |
| Oct | 2.6" | 3.3" | 0" | ✅ Rainfall sufficient |
| Nov | 2.6" | 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.
Basil 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.
Basil Planting Timeline — Coos County, OR
Basil Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 8 | Feb 8 – Feb 22 |
| Transplant Outdoors | March 29 | Mar 29 – Apr 12 |
| Direct Sow | March 29 | Mar 29 – Apr 19 |
| Harvest | May 24 | May 24 – Jul 26 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Transplant Outdoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | Harvest |
| June | Harvest |
| July | Harvest |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.6"/week · Natural rainfall sufficient
📅 Days to Maturity
50–75 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 9a
📆 Growing Season
242 days in Coos County
Growing Tips for Basil in Coos County
Direct sow Basil outdoors after March 22 in Coos County when soil has warmed and frost danger has passed.
General growing tips
Start seeds indoors or direct sow after last frost. Pinch flower buds to extend leaf production. Harvest leaves from the top down, cutting just above a leaf pair.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Isolate 150 ft between varieties. Different basil species can cross.
Basil in Other Locations
Frequently Asked Questions
When should I plant Basil in Coos County, OR?
Coos County is in Zone 9a with an average last frost of March 22. Plan your Basil 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.