Blog

When to Plant Cosmos in Lee County, VA

Lee County, Virginia Zone 7a June

What to do in June

Here's what deserves your attention in Lee County, Virginia this month. Everything below is tailored to Zone 7a and timed around your local frost dates.

Avg. last frost April 14
Avg. first frost October 23
Soil temp (4") 70°F
Watering Low
Pest pressure High
Daylight 14.5 hrs
  1. Bring in the cosmos

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

Looking ahead to July
  • First harvests: cosmos

Instant PDF download. No spam, unsubscribe any time.

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.

Lee County, Virginia is in USDA Zone 7a. The average last spring frost is April 14 and the first fall frost is October 23, giving you a growing season of approximately 192 days.

At an elevation of 2,513 feet, Lee County receives approximately 52.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°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
Lee County, VA (Zone 7a) Moderate season
192 days
Last Spring Frost April 14
192 growing days
First Fall Frost October 23

Lee County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.9

Drainage

Well Drained

Cosmos Planting Risk Windows

Early Start (70% safe) ✓ Fits season (11 days to spare)
Start indoors: Mar 11 Transplant: Apr 8 🌸 Bloom: Jun 17 – Oct 7
Recommended (50%) ✓ Fits season (10 days to spare)
Start indoors: Mar 17 Transplant: Apr 14 🌸 Bloom: Jun 23 – Oct 13
Safe Start (90%) ✓ Fits season (3 days to spare)
Start indoors: Apr 4 Transplant: May 2 🌸 Bloom: Jul 11 – Oct 31

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 Lee County

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

Soil pH

Your soil pH (5.3–6.9) overlaps with Cosmos's range (6.0–8.0), though not a perfect match.

Soil Texture

The silt loam soil in Lee County is excellent for Cosmos — good drainage, moisture retention, and nutrient holding capacity.

Drainage

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

Organic Matter

Organic matter is moderate (2.9%). Annual compost additions will help Cosmos.

How to Plant Cosmos

0.3"
Planting Depth
12"
Between Plants
18"
Between Rows

Succession Planting Cosmos

3
successive plantings in your 192-day season

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

Cosmos Water Budget

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

Monthly Watering Guide for Cosmos

Cosmos 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 Cosmos Needs Rainfall You Supplement Action
Jan 3.9" 0" ❄️ Dormant
Feb 4.4" 0" ❄️ Dormant
Mar 4.3" 0" ❄️ Dormant
Apr 2.2" 4.3" 0" ✅ Rainfall sufficient
May 2.2" 4.4" 0" ✅ Rainfall sufficient
Jun 2.2" 4.9" 0" ✅ Rainfall sufficient
Jul 2.2" 6.1" 0" ✅ Rainfall sufficient
Aug 2.2" 4.4" 0" ✅ Rainfall sufficient
Sep 2.2" 4.2" 0" ✅ Rainfall sufficient
Oct 2.2" 3.4" 0" ✅ Rainfall sufficient
Nov 4.1" 0" ❄️ Dormant
Dec 4" 0" ❄️ Dormant

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

Cosmos 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.

Cosmos needs ~1,312 GDD — county provides 3,360 GDD Excellent fit

Cosmos Planting Timeline — Lee County, VA

Cosmos Planting Calendar

Activity When Date Range
Start Indoors March 17 Mar 17 – Mar 31
Transplant Outdoors April 14 Apr 14 – Apr 28
Direct Sow April 14 Apr 14 – May 5
Bloom June 23 Jun 23 – Oct 13

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 Direct Sow
June Bloom
July Bloom
August Bloom
September Bloom
October Bloom
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–8 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

192 days in Lee County

Growing Tips for Cosmos in Lee County

Direct sow Cosmos outdoors after April 14 in Lee County when soil has warmed and frost danger has passed.

Common pests for Cosmos in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

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 Lee County, VA?

Lee County is in Zone 7a 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 Lee County, VA?

Lee County, Virginia is in USDA Hardiness Zone 7a. The average last spring frost is April 14 and first fall frost is October 23.

🌱

Your Lee County Garden Planner — Free

A 22-page printable planner built for Lee County (Zone 7a). 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 Lee 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.