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When to plant Vinca (Annual) in Barrow County County,

Barrow County County sits in cold Zone 8a. Plant Vinca (Annual) March 16–March 30 for the single annual harvest; the November 13 first frost closes the window.

When to Plant Vinca (Annual) in Barrow County, GA

Barrow County, Georgia Zone 8a June

Barrow County, Georgia gardeners: here's your June plan

If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.

Avg. last frost March 23
Avg. first frost November 13
Soil temp (4") 78°F
Watering Low
Pest pressure High
Daylight 14.3 hrs
  1. Sow vinca (annual) in trays indoors

    Your window is short. These crops want several weeks of indoor growth before they go outside.

  2. Start harvesting vinca (annual)

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

A few tasks this June that'll pay off in July
  • First harvests: vinca (annual)

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Annual vinca (Catharanthus roseus), also called Madagascar periwinkle, is one of the most heat- and drought-tolerant bedding plants available. Glossy foliage stays attractive all season while cheerful pinwheel blooms continue without deadheading. A top performer in hot, humid Southern summers where impatiens and begonias struggle. Self-cleaning; requires little maintenance once established.

Barrow County, Georgia is in USDA Zone 8a. The average last spring frost is March 23 and the first fall frost is November 13, giving you a growing season of approximately 235 days.

At an elevation of 438 feet, Barrow County receives approximately 60.5 inches of rainfall annually with predominantly clay loam soil. Summer highs average 93°F, providing good warmth for Vinca (Annual) during the growing season. Clay soil retains moisture well for Vinca (Annual), but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Vinca (Annual) root diseases.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant
Barrow County, GA (Zone 8a) Long season
235 days
Last Spring Frost March 23
235 growing days
First Fall Frost November 13
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Barrow County Soil Profile

Soil Type

Clay Loam

Soil pH

5.3-6.7

Drainage

Well Drained

Vinca (Annual) Planting Risk Windows

Early Start (70% safe) ✓ Fits season (32 days to spare)
Start indoors: Jan 3 Transplant: Mar 7 🌸 Bloom: May 16 – Oct 3
Recommended (50%) ✓ Fits season (32 days to spare)
Start indoors: Jan 12 Transplant: Mar 16 🌸 Bloom: May 25 – Oct 12
Safe Start (90%) ✓ Fits season (31 days to spare)
Start indoors: Jan 30 Transplant: Apr 3 🌸 Bloom: Jun 12 – Oct 30

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 Barrow County

How your county's soil matches Vinca (Annual)'s growing requirements.

Soil pH

Your soil pH (5.3–6.7) overlaps with Vinca (Annual)'s range (6.0–7.0), though not a perfect match.

Soil Texture

The clay loam soil in Barrow County is excellent for Vinca (Annual) — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

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

How to Plant Vinca (Annual)

0.1"
Planting Depth
10"
Between Plants
12"
Between Rows

Succession Planting Vinca (Annual)

3
successive plantings in your 235-day season

Sow every 8 weeks. Last sowing by Aug 15 to harvest before frost.

Vinca (Annual) 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 Vinca (Annual)

Vinca (Annual) 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 Vinca (Annual) Needs Rainfall You Supplement Action
Jan 4.5" 0" ❄️ Dormant
Feb 5.4" 0" ❄️ Dormant
Mar 2.2" 6.5" 0" ✅ Rainfall sufficient
Apr 2.2" 4.3" 0" ✅ Rainfall sufficient
May 2.2" 5.1" 0" ✅ Rainfall sufficient
Jun 2.2" 5.1" 0" ✅ Rainfall sufficient
Jul 2.2" 6.6" 0" ✅ Rainfall sufficient
Aug 2.2" 5.4" 0" ✅ Rainfall sufficient
Sep 2.2" 4.6" 0" ✅ Rainfall sufficient
Oct 2.2" 3.5" 0" ✅ Rainfall sufficient
Nov 2.2" 5.3" 0" ✅ Rainfall sufficient
Dec 4.2" 0" ❄️ Dormant

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

Vinca (Annual) 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.

Vinca (Annual) needs ~1,580 GDD — county provides 4,641 GDD Excellent fit

Vinca (Annual) Planting Timeline — Barrow County, GA

Vinca (Annual) Planting Calendar

Activity When Date Range
Start Indoors January 12 Jan 12 – Jan 26
Transplant Outdoors March 16 Mar 16 – Mar 30
Bloom May 25 May 25 – Oct 12

Plant 0.1" deep · 10" apart · Rows 12" apart

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 8a

📆 Growing Season

235 days in Barrow County

Growing Tips for Vinca (Annual) in Barrow County

Direct sow Vinca (Annual) outdoors after March 23 in Barrow County when soil has warmed and frost danger has passed.

With Barrow County's clay soil (33% clay), work in 3-4 inches of compost before planting Vinca (Annual). Avoid tilling when soil is wet to prevent compaction.

General growing tips

Start seeds indoors 10–12 weeks before last frost — germination requires warm soil (75–80°F) and darkness. Do not cover seeds deeply; they need just a light dusting. Direct sowing is rarely practiced due to slow seedling establishment. Transplant after soil warms and frost danger has passed. Excellent drought tolerance once established; avoid overwatering. Performs best in well-drained beds or containers in full sun.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Vinca (Annual) in Barrow County, GA?

Barrow County is in Zone 8a with an average last frost of March 23. Plan your Vinca (Annual) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Barrow County, GA?

Barrow County, Georgia is in USDA Hardiness Zone 8a. The average last spring frost is March 23 and first fall frost is November 13.

When should I plant Vinca (Annual) in Barrow County County, ?

In Barrow County County, , plant Vinca (Annual) after the last frost (around March 23) and before the first frost (around November 13). Best results when soil holds above 50°F.

What growing zone is Barrow County County, for Vinca (Annual)?

Barrow County County sits in USDA Zone 8a. Vinca (Annual) grows reliably in zones 3a through 11b, so it's a good fit here.

Can Vinca (Annual) grow in Barrow County County's climate?

Yes — Vinca (Annual) grows well in Barrow County County's temperate climate. Barrow County County averages a 235-day frost-free season, with last frost around March 23 and first frost around November 13.

🌱

Your Barrow County Garden Planner — Free

A 22-page printable planner built for Barrow 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.

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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 Barrow County, GA. 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.