Blog

When to Plant Lemon Balm in Union County, SC

Union County, South Carolina Zone 8a May

Your May planting checklist for Union County, South Carolina

May is a pivotal month for Union County, South Carolina gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 5
Avg. first frost October 31
Soil temp (4") 67°F
Watering Low
Pest pressure Moderate
Daylight 13.8 hrs
Before June arrives, get these ready
  • First harvests: lemon balm

Instant PDF download. No spam, unsubscribe any time.

Lemon balm is a vigorous perennial herb with bright green, lemon-scented leaves. It makes a refreshing tea and is easy to grow but can spread aggressively.

Union County, South Carolina is in USDA Zone 8a. 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 478 feet, Union County receives approximately 53.3 inches of rainfall annually with predominantly clay loam soil. Summer highs average 91°F, providing good warmth for Lemon Balm during the growing season. Clay soil retains moisture well for Lemon Balm, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Lemon Balm root diseases.

Union County, SC (Zone 8a) Long season
209 days
Last Spring Frost April 5
209 growing days
First Fall Frost October 31

Union County Soil Profile

Soil Type

Clay Loam

Soil pH

5.7-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (93 days to spare)
Transplant: Apr 3 🍅 Harvest: Jun 5 – Jul 24
Recommended (50%) ✓ Fits season (90 days to spare)
Transplant: Apr 12 🍅 Harvest: Jun 14 – Aug 2
Safe Start (90%) ✓ Fits season (98 days to spare)
Transplant: Apr 25 🍅 Harvest: Jun 27 – Aug 15

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 Union County

How your county's soil matches Lemon Balm's growing requirements.

Soil pH

Your soil pH (5.7–6.3) is within Lemon Balm's preferred range (5.5–7.5).

Soil Texture

The clay loam soil in Union County is excellent for Lemon Balm — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Lemon Balm.

How to Plant Lemon Balm

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

Succession Planting Lemon Balm

4
successive plantings in your 209-day season

Sow every 6.9 weeks. Last sowing by Aug 22 to harvest before frost.

Plant Water Budget

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

Monthly Watering Guide for Lemon Balm

Lemon Balm needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Lemon Balm Needs Rainfall You Supplement Action
Jan 5.1" 0" ❄️ Dormant
Feb 3.9" 0" ❄️ Dormant
Mar 4.5" 0" ❄️ Dormant
Apr 2.2" 4.5" 0" ✅ Rainfall sufficient
May 2.2" 3.8" 0" ✅ Rainfall sufficient
Jun 2.2" 5.2" 0" ✅ Rainfall sufficient
Jul 2.2" 5.5" 0" ✅ Rainfall sufficient
Aug 2.2" 4.5" 0" ✅ Rainfall sufficient
Sep 2.2" 4" 0" ✅ Rainfall sufficient
Oct 2.2" 3.5" 0" ✅ Rainfall sufficient
Nov 4.1" 0" ❄️ Dormant
Dec 4.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Union County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Lemon Balm 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.

Lemon Balm needs ~1,186 GDD — county provides 3,814 GDD Excellent fit

Lemon Balm Planting Timeline — Union County, SC

Lemon Balm Planting Calendar

Activity When Date Range
Transplant Outdoors April 12 Apr 12 – Apr 26
Harvest June 14 Jun 14 – Aug 2

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
October
November
December

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

60–70 days

🧪 Soil pH

Needs 5.5–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 8a

📆 Growing Season

209 days in Union County

Growing Tips for Lemon Balm in Union County

Direct sow Lemon Balm outdoors after April 05 in Union County when soil has warmed and frost danger has passed.

With Union County's clay soil (27% clay), work in 3-4 inches of compost before planting Lemon Balm. Avoid tilling when soil is wet to prevent compaction.

General growing tips

Start from seed, cuttings, or divisions. Contain in pots or use barriers to prevent spreading. Harvest frequently to keep plants bushy and prevent flowering.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Lemon Balm in Union County, SC?

Union County is in Zone 8a with an average last frost of April 5. Plan your Lemon Balm planting based on this frost date — see the calendar above for exact timing.

What planting zone is Union County, SC?

Union County, South Carolina is in USDA Hardiness Zone 8a. The average last spring frost is April 5 and first fall frost is October 31.

🌱

Your Union County Garden Planner — Free

A 24-page printable planner built for Union County (Zone 8a). 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 Union 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.