When to Plant Rosemary in Roane County, TN
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.
Roane County, Tennessee is in USDA Zone 7a. The average last spring frost is April 9 and the first fall frost is October 28, giving you a growing season of approximately 202 days.
At an elevation of 3,597 feet, Roane County receives approximately 54.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 92°F, providing good warmth for Rosemary during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Rosemary root diseases.
Roane County Soil Profile
Soil Type
Silt Loam
Soil pH
5.3-6.5
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 Roane County
How your county's soil matches Rosemary's growing requirements.
Soil pH
Your soil pH (5.3–6.5) is more acidic than Rosemary prefers (6.0–7.5). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Roane County is excellent for Rosemary — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Rosemary prefers dry conditions but your soil drains poorly. Use raised beds or mounded rows to prevent root rot.
Organic Matter
Organic matter is moderate (2.9%). Annual compost additions will help Rosemary.
How to Plant Rosemary
Succession Planting Rosemary
Sow every 9.1 weeks. Last sowing by May 01 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 | — | 4.1" | 0" | ❄️ Dormant |
| Feb | — | 4" | 0" | ❄️ Dormant |
| Mar | — | 4.8" | 0" | ❄️ Dormant |
| Apr | 1.3" | 4.7" | 0" | ✅ Rainfall sufficient |
| May | 1.3" | 3.9" | 0" | ✅ Rainfall sufficient |
| Jun | 1.3" | 4.9" | 0" | ✅ Rainfall sufficient |
| Jul | 1.3" | 6.2" | 0" | ✅ Rainfall sufficient |
| Aug | 1.3" | 4.6" | 0" | ✅ Rainfall sufficient |
| Sep | 1.3" | 3.8" | 0" | ✅ Rainfall sufficient |
| Oct | 1.3" | 4" | 0" | ✅ Rainfall sufficient |
| Nov | — | 4.4" | 0" | ❄️ Dormant |
| Dec | — | 4.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Roane 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 — Roane County, TN
Rosemary Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 16 | Apr 16 – Apr 30 |
| Harvest | July 9 | Jul 9 – Nov 26 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Transplant Outdoors |
| May | — |
| June | — |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | Harvest |
| November | Harvest |
| December | — |
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: too_acidic
🗺️ USDA Zone
Zone 7a
📆 Growing Season
202 days in Roane County
Growing Tips for Rosemary in Roane County
Direct sow Rosemary outdoors after April 09 in Roane County when soil has warmed and frost danger has passed.
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 Roane County, TN?
Roane County is in Zone 7a with an average last frost of April 9. Plan your Rosemary planting based on this frost date — see the calendar above for exact timing.
What planting zone is Roane County, TN?
Roane County, Tennessee is in USDA Hardiness Zone 7a. The average last spring frost is April 9 and first fall frost is October 28.
Plan Your Garden with Confidence
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