When to Plant Rosemary in Lake County, OH
This month in Lake County, Ohio
Here's what deserves your attention in Lake County, Ohio this month. Everything below is tailored to Zone 7a and timed around your local frost dates.
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Set out rosemary seedlings
Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.
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.
Lake County, Ohio is in USDA Zone 7a. The average last spring frost is May 5 and the first fall frost is October 13, giving you a growing season of approximately 161 days.
At an elevation of 740 feet, Lake County receives approximately 35.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Rosemary during the growing season.
Lake County Soil Profile
Soil Type
Silt Loam
Soil pH
6.3-7.2
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 Lake County
How your county's soil matches Rosemary's growing requirements.
Soil pH
Your soil pH (6.3–7.2) is within Rosemary's preferred range (6.0–7.5).
Soil Texture
The silt loam soil in Lake County is excellent for Rosemary — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.0%) — Rosemary will thrive.
How to Plant Rosemary
Succession Planting Rosemary
Sow every 9.1 weeks. Last sowing by Apr 16 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 | — | 1.7" | 0" | ❄️ Dormant |
| Feb | — | 1.4" | 0" | ❄️ Dormant |
| Mar | — | 2.6" | 0" | ❄️ Dormant |
| Apr | — | 3.9" | 0" | ❄️ Dormant |
| May | 1.3" | 3.9" | 0" | ✅ Rainfall sufficient |
| Jun | 1.3" | 4.8" | 0" | ✅ Rainfall sufficient |
| Jul | 1.3" | 4.1" | 0" | ✅ Rainfall sufficient |
| Aug | 1.3" | 3.7" | 0" | ✅ Rainfall sufficient |
| Sep | 1.3" | 3.1" | 0" | ✅ Rainfall sufficient |
| Oct | 1.3" | 2.5" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.3" | 0" | ❄️ Dormant |
| Dec | — | 1.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Lake 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 — Lake County, OH
Rosemary Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 12 | May 12 – May 26 |
| Harvest | August 4 | Aug 4 – Dec 22 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Transplant Outdoors |
| June | — |
| July | — |
| 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: ideal
🗺️ USDA Zone
Zone 7a
📆 Growing Season
161 days in Lake County
Growing Tips for Rosemary in Lake County
Direct sow Rosemary outdoors after May 05 in Lake County when soil has warmed and frost danger has passed.
Your 161.0-day growing season in Lake 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 Lake County, OH?
Lake County is in Zone 7a with an average last frost of May 5. Plan your Rosemary planting based on this frost date — see the calendar above for exact timing.
What planting zone is Lake County, OH?
Lake County, Ohio is in USDA Hardiness Zone 7a. The average last spring frost is May 5 and first fall frost is October 13.
Your Lake County Garden Planner — Free
A 24-page printable planner built for Lake 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.