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

Cullman County County's 219-day season only supports one Vinca (Annual) planting per year. Sow between March 21 and April 4 for the best chance at full maturity before November 2.

When to Plant Vinca (Annual) in Cullman County, AL

Cullman County, Alabama Zone 8a June

Your June planting checklist for Cullman County, Alabama

Here's what deserves your attention in Cullman County, Alabama this month. Everything below is tailored to Zone 8a and timed around your local frost dates.

Avg. last frost March 28
Avg. first frost November 2
Soil temp (4") 79°F
Watering Low
Pest pressure High
Daylight 14.3 hrs
  1. Get vinca (annual) seeds going inside

    Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.

  2. Bring in the vinca (annual)

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

Coming up in July — start thinking about
  • 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.

Cullman County, Alabama is in USDA Zone 8a. The average last spring frost is March 28 and the first fall frost is November 2, giving you a growing season of approximately 219 days.

At an elevation of 347 feet, Cullman County receives approximately 53.1 inches of rainfall annually with predominantly clay loam soil. Summer highs average 91°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
Cullman County, AL (Zone 8a) Long season
219 days
Last Spring Frost March 28
219 growing days
First Fall Frost November 2

Cullman County Soil Profile

Soil Type

Clay Loam

Soil pH

5.4-6.8

Drainage

Well Drained

Vinca (Annual) Planting Risk Windows

Early Start (70% safe) ✓ Fits season (17 days to spare)
Start indoors: Jan 10 Transplant: Mar 14 🌸 Bloom: May 23 – Oct 10
Recommended (50%) ✓ Fits season (16 days to spare)
Start indoors: Jan 17 Transplant: Mar 21 🌸 Bloom: May 30 – Oct 17
Safe Start (90%) ✓ Fits season (14 days to spare)
Start indoors: Feb 8 Transplant: Apr 12 🌸 Bloom: Jun 21 – Nov 8

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 Cullman County

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

Soil pH

Your soil pH (5.4–6.8) overlaps with Vinca (Annual)'s range (6.0–7.0), though not a perfect match.

Soil Texture

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

Drainage

Vinca (Annual) prefers dry conditions but your soil drains poorly. Use raised beds or mounded rows to prevent root rot.

Organic Matter

Organic matter is moderate (2.7%). 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 219-day season

Sow every 8 weeks. Last sowing by Aug 04 to harvest before frost.

Vinca (Annual) Water Budget

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

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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" 0" ❄️ Dormant
Feb 4" 0" ❄️ Dormant
Mar 2.2" 5.3" 0" ✅ Rainfall sufficient
Apr 2.2" 4.4" 0" ✅ Rainfall sufficient
May 2.2" 4.3" 0" ✅ Rainfall sufficient
Jun 2.2" 4.8" 0" ✅ Rainfall sufficient
Jul 2.2" 5.2" 0" ✅ Rainfall sufficient
Aug 2.2" 5.4" 0" ✅ Rainfall sufficient
Sep 2.2" 4" 0" ✅ Rainfall sufficient
Oct 2.2" 3.3" 0" ✅ Rainfall sufficient
Nov 2.2" 4.4" 0" ✅ Rainfall sufficient
Dec 3.9" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Cullman 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 ~1,460 GDD — county provides 3,996 GDD Excellent fit

Vinca (Annual) Planting Timeline — Cullman County, AL

Vinca (Annual) Planting Calendar

Activity When Date Range
Start Indoors January 17 Jan 17 – Jan 31
Transplant Outdoors March 21 Mar 21 – Apr 4
Bloom May 30 May 30 – Oct 17

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

Month-by-Month Timeline

MonthActivities
January Start Indoors
February
March Transplant Outdoors
April Transplant Outdoors
May Bloom
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

70–90 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 8a

📆 Growing Season

219 days in Cullman County

Growing Tips for Vinca (Annual) in Cullman County

Direct sow Vinca (Annual) outdoors after March 28 in Cullman County when soil has warmed and frost danger has passed.

With Cullman County's clay soil (30% 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 Cullman County, AL?

Cullman County is in Zone 8a with an average last frost of March 28. Plan your Vinca (Annual) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Cullman County, AL?

Cullman County, Alabama is in USDA Hardiness Zone 8a. The average last spring frost is March 28 and first fall frost is November 2.

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

In Cullman County, , plant Vinca (Annual) after the last frost (around March 28) and before the first frost (around November 2). Best results when soil holds above 50°F.

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

Cullman 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 Cullman County's climate?

Yes — Vinca (Annual) grows well in Cullman County's temperate climate. Cullman County averages a 219-day frost-free season, with last frost around March 28 and first frost around November 2.

🌱

Your Cullman County Garden Planner — Free

A 22-page printable planner built for Cullman 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 Cullman County, AL. 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.