When to Plant Rosemary in Lane County, OR
Rosemary is an aromatic evergreen shrub with needle-like leaves and a piney, citrus flavor. It is a Mediterranean herb that thrives in warm, dry conditions.
Lane County, Oregon is in USDA Zone 8a. The average last spring frost is April 21 and the first fall frost is October 25, giving you a growing season of approximately 187 days.
At an elevation of 48 feet, Lane County receives approximately 50.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Rosemary to ensure they mature before fall. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Rosemary root diseases.
Lane County Soil Profile
Soil Type
Silt Loam
Soil pH
5.7-6.4
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 Lane County
How your county's soil matches Rosemary's growing requirements.
Soil pH
Your soil pH (5.7–6.4) overlaps with Rosemary's range (6.0–7.5), though not a perfect match.
Soil Texture
The silt loam soil in Lane County is excellent for Rosemary — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.3%) — Rosemary will thrive.
How to Plant Rosemary
Succession Planting Rosemary
Sow every 9.1 weeks. Last sowing by Apr 28 to harvest before frost.
Plant Water Budget
Monthly Watering Guide for Rosemary
Rosemary needs approximately 0.3 inches of water per week (1.3" per month). Here's how your county's rainfall compares month by month.
| Month | Rosemary Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 7.6" | 0" | ❄️ Dormant |
| Feb | — | 5.3" | 0" | ❄️ Dormant |
| Mar | — | 5.3" | 0" | ❄️ Dormant |
| Apr | 1.3" | 4" | 0" | ✅ Rainfall sufficient |
| May | 1.3" | 2.5" | 0" | ✅ Rainfall sufficient |
| Jun | 1.3" | 1.6" | 0" | ✅ Rainfall sufficient |
| Jul | 1.3" | 0.8" | 0.5" | 💧 Light watering |
| Aug | 1.3" | 0.9" | 0.4" | 💧 Light watering |
| Sep | 1.3" | 2" | 0" | ✅ Rainfall sufficient |
| Oct | 1.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Nov | — | 8.3" | 0" | ❄️ Dormant |
| Dec | — | 8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Lane County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Rosemary 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.
Rosemary Planting Timeline — Lane County, OR
Rosemary Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 28 | Apr 28 – May 12 |
| Harvest | July 21 | Jul 21 – Dec 8 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Transplant Outdoors |
| May | Transplant Outdoors |
| June | — |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | Harvest |
| November | Harvest |
| December | Harvest |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.3"/week · Natural rainfall sufficient
📅 Days to Maturity
80–180 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 8a
📆 Growing Season
187 days in Lane County
Growing Tips for Rosemary in Lane County
Direct sow Rosemary outdoors after April 21 in Lane County when soil has warmed and frost danger has passed.
Your 187.0-day growing season in Lane County is tight for Rosemary (80.0-180.0 days to maturity). Start indoors and choose early-maturing varieties.
General growing tips
Grow in well-drained soil and avoid overwatering. In cold climates, grow in containers and bring indoors for winter. Propagate from stem cuttings for faster results than seed.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Rosemary in Other Locations
Frequently Asked Questions
When should I plant Rosemary in Lane County, OR?
Lane County is in Zone 8a with an average last frost of April 21. Plan your Rosemary planting based on this frost date — see the calendar above for exact timing.
What planting zone is Lane County, OR?
Lane County, Oregon is in USDA Hardiness Zone 8a. The average last spring frost is April 21 and first fall frost is October 25.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Lane County gardeners in Zone 8a organize planting dates, track what's growing, and never miss a planting window.
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