When to Plant Rosemary in Henderson County, KY
Your May gardening checklist
May is a pivotal month for Henderson County, Kentucky gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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.
Henderson County, Kentucky is in USDA Zone 7a. The average last spring frost is April 5 and the first fall frost is October 31, giving you a growing season of approximately 209 days.
At an elevation of 3,992 feet, Henderson County receives approximately 47.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Rosemary during the growing season.
Henderson County Soil Profile
Soil Type
Silt Loam
Soil pH
5.3-7.1
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 Henderson County
How your county's soil matches Rosemary's growing requirements.
Soil pH
Your soil pH (5.3–7.1) overlaps with Rosemary's range (6.0–7.5), though not a perfect match.
Soil Texture
The silt loam soil in Henderson 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 (2.6%). Annual compost additions will help Rosemary.
How to Plant Rosemary
Succession Planting Rosemary
Sow every 9.1 weeks. Last sowing by May 04 to harvest before frost.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
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 | — | 3.6" | 0" | ❄️ Dormant |
| Feb | — | 3.3" | 0" | ❄️ Dormant |
| Mar | — | 4.9" | 0" | ❄️ Dormant |
| Apr | 1.3" | 4" | 0" | ✅ Rainfall sufficient |
| May | 1.3" | 4.2" | 0" | ✅ Rainfall sufficient |
| Jun | 1.3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Jul | 1.3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Aug | 1.3" | 4.9" | 0" | ✅ Rainfall sufficient |
| Sep | 1.3" | 3.3" | 0" | ✅ Rainfall sufficient |
| Oct | 1.3" | 2.8" | 0" | ✅ Rainfall sufficient |
| Nov | — | 3.5" | 0" | ❄️ Dormant |
| Dec | — | 3.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Henderson 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 — Henderson County, KY
Rosemary Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 12 | Apr 12 – Apr 26 |
| Harvest | July 5 | Jul 5 – Nov 22 |
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
209 days in Henderson County
Growing Tips for Rosemary in Henderson County
Direct sow Rosemary outdoors after April 05 in Henderson 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 Henderson County, KY?
Henderson County is in Zone 7a with an average last frost of April 5. Plan your Rosemary planting based on this frost date — see the calendar above for exact timing.
What planting zone is Henderson County, KY?
Henderson County, Kentucky is in USDA Hardiness Zone 7a. The average last spring frost is April 5 and first fall frost is October 31.
Your Henderson County Garden Planner — Free
A 24-page printable planner built for Henderson County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.