Blog

When to Plant Rosemary in Hardin County, TN

Hardin County, Tennessee Zone 7b May

Top priorities for Hardin County, Tennessee gardeners in May

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Hardin County, Tennessee.

Avg. last frost March 31
Avg. first frost October 28
Soil temp (4") 62°F
Watering Low
Pest pressure Moderate
Daylight 13.9 hrs
Looking ahead to June
  • First harvests: rosemary

Instant PDF download. No spam, unsubscribe any time.

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.

Hardin County, Tennessee is in USDA Zone 7b. The average last spring frost is March 31 and the first fall frost is October 28, giving you a growing season of approximately 211 days.

At an elevation of 3,095 feet, Hardin County receives approximately 53.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 93°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.

Hardin County, TN (Zone 7b) Long season
211 days
Last Spring Frost March 31
211 growing days
First Fall Frost October 28

Hardin County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Mar 31 🍅 Harvest: Jun 23 – Nov 10
Recommended (50%) ✗ May not fit
Transplant: Apr 7 🍅 Harvest: Jun 30 – Nov 17
Safe Start (90%) ✗ May not fit
Transplant: Apr 23 🍅 Harvest: Jul 16 – Dec 3

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 Hardin County

How your county's soil matches Rosemary's growing requirements.

Soil pH

Your soil pH (5.4–6.7) overlaps with Rosemary's range (6.0–7.5), though not a perfect match.

Soil Texture

The silt loam soil in Hardin County is excellent for Rosemary — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.9%). Annual compost additions will help Rosemary.

How to Plant Rosemary

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Succession Planting Rosemary

3
successive plantings in your 211-day season

Sow every 9.1 weeks. Last sowing by May 01 to harvest before frost.

Plant Water Budget

Plant needs
0.3″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 4.2" 0" ❄️ Dormant
Feb 4.2" 0" ❄️ Dormant
Mar 1.3" 5.2" 0" ✅ Rainfall sufficient
Apr 1.3" 3.7" 0" ✅ Rainfall sufficient
May 1.3" 4.7" 0" ✅ Rainfall sufficient
Jun 1.3" 4.8" 0" ✅ Rainfall sufficient
Jul 1.3" 6" 0" ✅ Rainfall sufficient
Aug 1.3" 4.9" 0" ✅ Rainfall sufficient
Sep 1.3" 3.5" 0" ✅ Rainfall sufficient
Oct 1.3" 3.9" 0" ✅ Rainfall sufficient
Nov 4.3" 0" ❄️ Dormant
Dec 4.1" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Oct in Hardin 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 needs ~2,568 GDD — county provides 4,167 GDD Excellent fit

Rosemary Planting Timeline — Hardin County, TN

Rosemary Planting Calendar

Activity When Date Range
Transplant Outdoors April 7 Apr 7 – Apr 21
Harvest June 30 Jun 30 – Nov 17

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April Transplant Outdoors
May
June Harvest
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 7b

📆 Growing Season

211 days in Hardin County

Growing Tips for Rosemary in Hardin County

Direct sow Rosemary outdoors after March 31 in Hardin 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 →

Frequently Asked Questions

When should I plant Rosemary in Hardin County, TN?

Hardin County is in Zone 7b with an average last frost of March 31. Plan your Rosemary planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hardin County, TN?

Hardin County, Tennessee is in USDA Hardiness Zone 7b. The average last spring frost is March 31 and first fall frost is October 28.

🌱

Your Hardin County Garden Planner — Free

A 24-page printable planner built for Hardin County (Zone 7b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Hardin County, TN. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.