When to Plant Eggplant in Coos County, OR
Eggplant is a heat-loving solanaceous crop that produces glossy fruits in purple, white, or striped varieties. It requires long, warm growing seasons for best production.
Coos County, Oregon is in USDA Zone 8b. 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 Eggplant 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 Eggplant's growing requirements.
Soil pH
Your soil pH (5.4–6.8) overlaps with Eggplant's range (5.5–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Coos County is excellent for Eggplant — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.7%) — Eggplant will thrive.
How to Plant Eggplant
Succession Planting Eggplant
Sow every 7.4 weeks. Last sowing by Aug 26 to harvest before frost.
Plant Water Budget
Monthly Watering Guide for Eggplant
Eggplant needs approximately 1.1 inches of water per week (4.8" per month). Here's how your county's rainfall compares month by month.
| Month | Eggplant Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 5.5" | 0" | ❄️ Dormant |
| Feb | — | 4.5" | 0" | ❄️ Dormant |
| Mar | 4.8" | 4.4" | 0.4" | 💧 Light watering |
| Apr | 4.8" | 3.1" | 1.7" | 💧 Light watering |
| May | 4.8" | 2.3" | 2.5" | 🚿 Regular watering |
| Jun | 4.8" | 1.6" | 3.2" | 🚿 Regular watering |
| Jul | 4.8" | 0.6" | 4.2" | 🚿 Regular watering |
| Aug | 4.8" | 0.8" | 4" | 🚿 Regular watering |
| Sep | 4.8" | 1.4" | 3.4" | 🚿 Regular watering |
| Oct | 4.8" | 3.3" | 1.5" | 💧 Light watering |
| Nov | 4.8" | 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.
Eggplant 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.
Eggplant Planting Timeline — Coos County, OR
Eggplant Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 18 | Jan 18 – Feb 1 |
| Transplant Outdoors | April 5 | Apr 5 – Apr 19 |
| Direct Sow | March 29 | Mar 29 – Apr 19 |
| Harvest | June 14 | Jun 14 – Aug 16 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Start Indoors |
| March | Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | — |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1.1"/week · 1-2 times/week
📅 Days to Maturity
65–85 days
🧪 Soil pH
Needs 5.5–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 8b
📆 Growing Season
242 days in Coos County
Growing Tips for Eggplant in Coos County
Direct sow Eggplant outdoors after March 22 in Coos County when soil has warmed and frost danger has passed.
Common pests for Eggplant in this region include tomato hornworm and aphids. Use row covers early in the season and inspect plants weekly.
General growing tips
Start seeds indoors 8-10 weeks before last frost. Transplant only after nighttime temperatures stay above 55F. Mulch to retain moisture and warmth around roots.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Eggplant in Other Locations
Frequently Asked Questions
When should I plant Eggplant in Coos County, OR?
Coos County is in Zone 8b with an average last frost of March 22. Plan your Eggplant 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 8b. The average last spring frost is March 22 and first fall frost is November 19.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Coos County gardeners in Zone 8b organize planting dates, track what's growing, and never miss a planting window.
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