When to Plant Rosemary in King William County, VA
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.
King William County, Virginia is in USDA Zone 7a. The average last spring frost is April 6 and the first fall frost is November 2, giving you a growing season of approximately 210 days.
At an elevation of 110 feet, King William County receives approximately 40.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 94°F, providing good warmth for Rosemary during the growing season.
King William County Soil Profile
Soil Type
Silt Loam
Soil pH
5.3-7
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 King William County
How your county's soil matches Rosemary's growing requirements.
Soil pH
Your soil pH (5.3–7.0) overlaps with Rosemary's range (6.0–7.5), though not a perfect match.
Soil Texture
The silt loam soil in King William County is excellent for Rosemary — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.8%). Annual compost additions will help Rosemary.
How to Plant Rosemary
Succession Planting Rosemary
Sow every 9.1 weeks. Last sowing by May 06 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 | — | 3.2" | 0" | ❄️ Dormant |
| Feb | — | 3.3" | 0" | ❄️ Dormant |
| Mar | — | 3.5" | 0" | ❄️ Dormant |
| Apr | 1.3" | 2.8" | 0" | ✅ Rainfall sufficient |
| May | 1.3" | 3.7" | 0" | ✅ Rainfall sufficient |
| Jun | 1.3" | 3.5" | 0" | ✅ Rainfall sufficient |
| Jul | 1.3" | 3.8" | 0" | ✅ Rainfall sufficient |
| Aug | 1.3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Sep | 1.3" | 3" | 0" | ✅ Rainfall sufficient |
| Oct | 1.3" | 2.3" | 0" | ✅ Rainfall sufficient |
| Nov | 1.3" | 3.3" | 0" | ✅ Rainfall sufficient |
| Dec | — | 3.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Nov in King William 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 — King William County, VA
Rosemary Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 13 | Apr 13 – Apr 27 |
| Harvest | July 6 | Jul 6 – Nov 23 |
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: acceptable
🗺️ USDA Zone
Zone 7a
📆 Growing Season
210 days in King William County
Growing Tips for Rosemary in King William County
Direct sow Rosemary outdoors after April 06 in King William 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 King William County, VA?
King William County is in Zone 7a with an average last frost of April 6. Plan your Rosemary planting based on this frost date — see the calendar above for exact timing.
What planting zone is King William County, VA?
King William County, Virginia is in USDA Hardiness Zone 7a. The average last spring frost is April 6 and first fall frost is November 2.
Plan Your Garden with Confidence
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