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When to Plant Catnip in Williamsburg County, SC

Williamsburg County, South Carolina Zone 8b May

May in the garden — Williamsburg County, South Carolina

Each item below is timed to Williamsburg County, South Carolina's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost March 22
Avg. first frost November 13
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 13.7 hrs
  1. Basket week: catnip

    If you can't use it all right away, check the food-preservation section of your planner.

June will be here before you know it — start on
  • First harvests: catnip

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Catnip is a hardy perennial herb in the mint family known for its effect on cats. It also makes a calming tea and is a useful companion plant that repels some pests.

Williamsburg County, South Carolina is in USDA Zone 8b. The average last spring frost is March 22 and the first fall frost is November 13, giving you a growing season of approximately 236 days.

At an elevation of 139 feet, Williamsburg County receives approximately 52.7 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 92°F, providing good warmth for Catnip during the growing season. Sandy soil warms quickly in spring — great for early planting — but Catnip will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Catnip root diseases.

Williamsburg County, SC (Zone 8b) Long season
236 days
Last Spring Frost March 22
236 growing days
First Fall Frost November 13
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Williamsburg County Soil Profile

Soil Type

Sandy Loam

Soil pH

5-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (105 days to spare)
Transplant: Mar 17 🍅 Harvest: May 19 – Jul 21
Recommended (50%) ✓ Fits season (103 days to spare)
Transplant: Mar 29 🍅 Harvest: May 31 – Aug 2
Safe Start (90%) ✓ Fits season (100 days to spare)
Transplant: Apr 15 🍅 Harvest: Jun 17 – Aug 19

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 Williamsburg County

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

Soil pH

Your soil pH (5.0–6.4) is more acidic than Catnip prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

Sandy soil in Williamsburg County warms quickly in spring but drains fast. Catnip will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Catnip prefers dry conditions but your soil drains poorly. Use raised beds or mounded rows to prevent root rot.

Organic Matter

Organic matter is low (1.9%). Add 2-3 inches of compost before planting Catnip.

How to Plant Catnip

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

Succession Planting Catnip

4
successive plantings in your 236-day season

Sow every 6.9 weeks. Last sowing by Aug 25 to harvest before frost.

Plant Water Budget

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

Monthly Watering Guide for Catnip

Catnip 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 Catnip Needs Rainfall You Supplement Action
Jan 4.2" 0" ❄️ Dormant
Feb 4.5" 0" ❄️ Dormant
Mar 2.2" 4.4" 0" ✅ Rainfall sufficient
Apr 2.2" 4.5" 0" ✅ Rainfall sufficient
May 2.2" 4.1" 0" ✅ Rainfall sufficient
Jun 2.2" 4.5" 0" ✅ Rainfall sufficient
Jul 2.2" 5.9" 0" ✅ Rainfall sufficient
Aug 2.2" 5.2" 0" ✅ Rainfall sufficient
Sep 2.2" 3.6" 0" ✅ Rainfall sufficient
Oct 2.2" 3" 0" ✅ Rainfall sufficient
Nov 2.2" 4.3" 0" ✅ Rainfall sufficient
Dec 4.4" 0" ❄️ Dormant

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

Catnip 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.

Catnip needs ~1,330 GDD — county provides 4,484 GDD Excellent fit

Catnip Planting Timeline — Williamsburg County, SC

Catnip Planting Calendar

Activity When Date Range
Transplant Outdoors March 29 Mar 29 – Apr 12
Harvest May 31 May 31 – Aug 2

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

60–80 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 8b

📆 Growing Season

236 days in Williamsburg County

Growing Tips for Catnip in Williamsburg County

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

Sandy soil in Williamsburg County dries quickly — mulch Catnip with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

General growing tips

Direct sow or start indoors. Catnip is very easy to grow and can become invasive. Harvest leaves before flowering for tea. Protect young plants from cats.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Catnip in Williamsburg County, SC?

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

What planting zone is Williamsburg County, SC?

Williamsburg County, South Carolina is in USDA Hardiness Zone 8b. The average last spring frost is March 22 and first fall frost is November 13.

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Your Williamsburg County Garden Planner — Free

A 24-page printable planner built for Williamsburg 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 Williamsburg 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.