Blog

When to Plant Cosmos in Campbell County, VA

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.

Campbell County, Virginia is in USDA Zone 7b. The average last spring frost is April 14 and the first fall frost is October 26, giving you a growing season of approximately 195 days.

At an elevation of 975 feet, Campbell County receives approximately 54.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Cosmos during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Cosmos root diseases.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Campbell County, VA (Zone 7b) Moderate season
195 days
Last Spring Frost April 14
195 growing days
First Fall Frost October 26

Campbell County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.8

Drainage

Well Drained

Monthly Watering Guide for Cosmos

Cosmos needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Cosmos Needs Rainfall You Supplement Action
Jan 4.6" 0" ❄️ Dormant
Feb 4.2" 0" ❄️ Dormant
Mar 5.3" 0" ❄️ Dormant
Apr 4.3" 4.4" 0" ✅ Rainfall sufficient
May 4.3" 3.7" 0.6" 💧 Light watering
Jun 4.3" 4.9" 0" ✅ Rainfall sufficient
Jul 4.3" 5.5" 0" ✅ Rainfall sufficient
Aug 4.3" 5.1" 0" ✅ Rainfall sufficient
Sep 4.3" 4.5" 0" ✅ Rainfall sufficient
Oct 4.3" 3.4" 0.9" 💧 Light watering
Nov 4.3" 0" ❄️ Dormant
Dec 4.6" 0" ❄️ Dormant

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

Cosmos Planting Timeline — Campbell County, VA

Cosmos Planting Calendar

Activity When Date Range
Start Indoors March 17 Mar 17 – Mar 31
Transplant Outdoors April 7 Apr 7 – Apr 21
Direct Sow April 7 Apr 7 – Apr 28
Bloom June 16 Jun 16 – Oct 20

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

Month-by-Month Timeline

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

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 7b

📆 Growing Season

195 days in Campbell County

Growing Tips for Campbell 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 Campbell County, VA?

Campbell County is in Zone 7b with an average last frost of April 14. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.

What planting zone is Campbell County, VA?

Campbell County, Virginia is in USDA Hardiness Zone 7b. The average last spring frost is April 14 and first fall frost is October 26.

🌱

Your Campbell County Garden Planner — Free

A 22-page printable planner built for Campbell 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 Campbell County, VA. 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.