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When to Plant Cosmos in Berkeley County, SC

Berkeley County, South Carolina Zone 8b June

What to do in June

June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Berkeley County, South Carolina.

Avg. last frost February 29
Avg. first frost November 23
Soil temp (4") 82°F
Watering Low
Pest pressure High
Daylight 14.2 hrs

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Cosmos (Cosmos bipinnatus) is an airy, feathery-foliaged cottage garden annual from Mexico that thrives on neglect. It produces delicate daisy-like blooms in shades of pink, white, and magenta from midsummer until frost. Cosmos is a prolific self-sower — once established in a garden it often returns year after year without replanting. Excellent habitat plant for beneficial insects.

Berkeley County, South Carolina is in USDA Zone 8b. The average last spring frost is March 1 and the first fall frost is November 23, giving you a growing season of approximately 267 days.

At an elevation of 441 feet, Berkeley County receives approximately 52.8 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 93°F, providing good warmth for Cosmos during the growing season. Sandy soil warms quickly in spring — great for early planting — but Cosmos will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Cosmos root diseases.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Berkeley County, SC (Zone 8b) Long season
267 days
Last Spring Frost March 1
267 growing days
First Fall Frost November 23
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Berkeley County Soil Profile

Soil Type

Sandy Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Cosmos Planting Timeline — Berkeley County, SC

Cosmos Planting Calendar

Activity When Date Range
Start Indoors February 1 Feb 1 – Feb 15
Transplant Outdoors February 8 Feb 8 – Feb 22
Direct Sow February 8 Feb 8 – Mar 1
Bloom April 19 Apr 19 – Sep 20

Plant 0.3" deep · 12" apart · Rows 18" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors Transplant Outdoors Direct Sow
March Direct Sow
April Bloom
May Bloom
June Bloom
July Bloom
August Bloom
September Bloom
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–8 · Your soil: N/A

🗺️ USDA Zone

Zone 8b

📆 Growing Season

267 days in Berkeley County

Growing Tips for Berkeley County

Direct-sow after last frost; cosmos germinates readily at 65-80°F in 7-10 days. Avoid rich soil — excess fertility produces lush foliage at the expense of blooms. Cosmos tolerates poor, dry soil exceptionally well. Pinch seedlings at 8 inches to encourage branching. Self-sows freely; allow some seed heads to mature and drop for a no-fuss perennial effect in warm climates.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cosmos in Berkeley County, SC?

Berkeley County is in Zone 8b with an average last frost of March 1. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.

What planting zone is Berkeley County, SC?

Berkeley County, South Carolina is in USDA Hardiness Zone 8b. The average last spring frost is March 1 and first fall frost is November 23.

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Your Berkeley County Garden Planner — Free

A 22-page printable planner built for Berkeley 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 Berkeley County, SC. Local conditions may vary. Last updated: June 2026.

Sources & credits

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