When to plant Rosemary in Jackson County, IL
Jackson County sits in cold Zone 7a. Plant Rosemary April 17–May 1 for the single annual harvest; the October 21 first frost closes the window.
When to Plant Rosemary in Jackson County, IL
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.
Jackson County, Illinois is in USDA Zone 7a. The average last spring frost is April 10 and the first fall frost is October 21, giving you a growing season of approximately 194 days.
At an elevation of 1,046 feet, Jackson County receives approximately 38.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Rosemary during the growing season.
Jackson County Soil Profile
Soil Type
Silt Loam
Soil pH
6.1-7.1
Drainage
Well Drained
Monthly Watering Guide for Rosemary
Rosemary needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Rosemary Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.8" | 0" | ❄️ Dormant |
| Feb | — | 1.7" | 0" | ❄️ Dormant |
| Mar | — | 2.7" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.4" | 0.9" | 💧 Light watering |
| May | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Jun | 4.3" | 5.8" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Sep | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Oct | 4.3" | 2.9" | 1.4" | 💧 Light watering |
| Nov | — | 2.5" | 0" | ❄️ Dormant |
| Dec | — | 2.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Jackson County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Rosemary Planting Timeline — Jackson County, IL
Rosemary Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 17 | Apr 17 – May 1 |
| Harvest | July 10 | Jul 10 – Nov 27 |
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 | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Low — drought tolerant
📅 Days to Maturity
80–180 days
🧪 Soil pH
Needs 6–7.5 · Your soil: N/A
🗺️ USDA Zone
Zone 7a
📆 Growing Season
194 days in Jackson County
Growing Tips for Jackson County
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 Jackson County, IL?
Jackson County is in Zone 7a with an average last frost of April 10. Plan your Rosemary planting based on this frost date — see the calendar above for exact timing.
What planting zone is Jackson County, IL?
Jackson County, Illinois is in USDA Hardiness Zone 7a. The average last spring frost is April 10 and first fall frost is October 21.
When should I plant Rosemary in Jackson County, IL?
In Jackson County, IL, plant Rosemary after the last frost (around April 10) and before the first frost (around October 21). Best results when soil holds above 50°F.
What growing zone is Jackson County, IL for Rosemary?
Jackson County sits in USDA Zone 7a. Rosemary grows reliably in zones 7a through 10b, so it's a good fit here.
Can Rosemary grow in Jackson County's climate?
Yes — Rosemary grows well in Jackson County's temperate climate. Jackson County averages a 194-day frost-free season, with last frost around April 10 and first frost around October 21.
Your Jackson County Garden Planner — Free
A 22-page printable planner built for Jackson 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.