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When to Plant Rosemary in Richland County, SC

Richland County, South Carolina Zone 8b May

What to do in May

Welcome to May in Zone 8b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost March 22
Avg. first frost November 10
Soil temp (4") 70°F
Watering Low
Pest pressure High
Daylight 13.8 hrs
Looking ahead to June
  • First harvests: rosemary

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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.

Richland County, South Carolina is in USDA Zone 8b. The average last spring frost is March 22 and the first fall frost is November 10, giving you a growing season of approximately 233 days.

At an elevation of 88 feet, Richland County receives approximately 57.8 inches of rainfall annually with predominantly clay loam soil. Summer highs average 97°F, so Rosemary may need afternoon shade and extra watering during peak heat. Clay soil retains moisture well for Rosemary, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Rosemary root diseases.

Richland County, SC (Zone 8b) Long season
233 days
Last Spring Frost March 22
233 growing days
First Fall Frost November 10
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Richland County Soil Profile

Soil Type

Clay Loam

Soil pH

5.7-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Mar 24 🍅 Harvest: Jun 16 – Nov 3
Recommended (50%) ✓ Fits season (2 days to spare)
Transplant: Mar 29 🍅 Harvest: Jun 21 – Nov 8
Safe Start (90%) ✗ May not fit
Transplant: Apr 22 🍅 Harvest: Jul 15 – Dec 2

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 Richland County

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

Soil pH

Your soil pH (5.7–6.7) overlaps with Rosemary's range (6.0–7.5), though not a perfect match.

Soil Texture

The clay loam soil in Richland 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 (2.3%). 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 233-day season

Sow every 9.1 weeks. Last sowing by May 14 to harvest before frost.

Plant Water Budget

Plant needs
0.3″/week
Rainfall provides
1.0″/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 5.4" 0" ❄️ Dormant
Feb 4.9" 0" ❄️ Dormant
Mar 1.3" 4.7" 0" ✅ Rainfall sufficient
Apr 1.3" 4.8" 0" ✅ Rainfall sufficient
May 1.3" 3.9" 0" ✅ Rainfall sufficient
Jun 1.3" 5.6" 0" ✅ Rainfall sufficient
Jul 1.3" 6.5" 0" ✅ Rainfall sufficient
Aug 1.3" 5.2" 0" ✅ Rainfall sufficient
Sep 1.3" 4.5" 0" ✅ Rainfall sufficient
Oct 1.3" 3.7" 0" ✅ Rainfall sufficient
Nov 1.3" 4.3" 0" ✅ Rainfall sufficient
Dec 4.3" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Richland 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 ~2,958 GDD — county provides 5,300 GDD Excellent fit

Rosemary Planting Timeline — Richland County, SC

Rosemary Planting Calendar

Activity When Date Range
Transplant Outdoors March 29 Mar 29 – Apr 12
Harvest June 21 Jun 21 – Nov 8

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

Month-by-Month Timeline

MonthActivities
January
February
March Transplant Outdoors
April Transplant Outdoors
May
June Harvest
July Harvest
August Harvest
September Harvest
October Harvest
November Harvest
December
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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 8b

📆 Growing Season

233 days in Richland County

Growing Tips for Rosemary in Richland County

Direct sow Rosemary outdoors after March 22 in Richland County when soil has warmed and frost danger has passed.

With Richland County's clay soil (32% clay), work in 3-4 inches of compost before planting Rosemary. Avoid tilling when soil is wet to prevent compaction.

With summer highs reaching 97°F in Richland County, provide afternoon shade for Rosemary and water deeply in the morning.

With 58" of annual rainfall in Richland County, ensure good drainage for Rosemary — excess moisture can promote root rot and fungal diseases.

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 Richland County, SC?

Richland County is in Zone 8b with an average last frost of March 22. Plan your Rosemary planting based on this frost date — see the calendar above for exact timing.

What planting zone is Richland County, SC?

Richland County, South Carolina is in USDA Hardiness Zone 8b. The average last spring frost is March 22 and first fall frost is November 10.

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Your Richland County Garden Planner — Free

A 24-page printable planner built for Richland County (Zone 8b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Richland County, SC. 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.