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When to plant Vinca (Annual) in Kellerman, AL

Kellerman sits in cold Zone 8b. Plant Vinca (Annual) March 8–March 22 for the single annual harvest; the November 9 first frost closes the window.

When to Plant Vinca (Annual) in Kellerman, AL

Tuscaloosa County, Alabama Zone 8b July

July to-do list for Tuscaloosa County, Alabama

A quick July briefing for Tuscaloosa County, Alabama gardeners — what's urgent, what's next, and what can wait.

Avg. last frost March 22
Avg. first frost November 9
Soil temp (4") 86°F
Watering Low
Pest pressure High
Daylight 14 hrs
  1. It's harvest week for vinca (annual)

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

Get ahead of August
  • 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.

Kellerman, Alabama is in USDA Zone 8b. The average last spring frost is March 22 and the first fall frost is November 9, giving you a growing season of approximately 232 days.

At an elevation of 436 feet, Tuscaloosa County receives approximately 52.9 inches of rainfall annually with predominantly clay loam soil. Summer highs average 94°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
Kellerman, AL (Zone 8b) Long season
232 days
Last Spring Frost March 22
232 growing days
First Fall Frost November 9

Kellerman Soil Profile

Soil Type

Clay Loam

Soil pH

5.5-6.2

Drainage

Well Drained

Vinca (Annual) Planting Risk Windows

Early Start (70% safe) ✓ Fits season (22 days to spare)
Start indoors: Jan 2 Transplant: Feb 27 🌸 Bloom: May 8 – Oct 9
Recommended (50%) ✓ Fits season (22 days to spare)
Start indoors: Jan 11 Transplant: Mar 8 🌸 Bloom: May 17 – Oct 18
Safe Start (90%) ✓ Fits season (16 days to spare)
Start indoors: Feb 3 Transplant: Mar 31 🌸 Bloom: Jun 9 – Nov 10

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 Kellerman

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

Soil pH

Your soil pH (5.5–6.2) is more acidic than Vinca (Annual) prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.4%). 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 232-day season

Sow every 8 weeks. Last sowing by Aug 11 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 4.5" 0" ❄️ Dormant
Feb 4.7" 0" ❄️ Dormant
Mar 2.2" 5.2" 0" ✅ Rainfall sufficient
Apr 2.2" 4.1" 0" ✅ Rainfall sufficient
May 2.2" 3.6" 0" ✅ Rainfall sufficient
Jun 2.2" 4.7" 0" ✅ Rainfall sufficient
Jul 2.2" 5.3" 0" ✅ Rainfall sufficient
Aug 2.2" 4.4" 0" ✅ Rainfall sufficient
Sep 2.2" 3.5" 0" ✅ Rainfall sufficient
Oct 2.2" 3.9" 0" ✅ Rainfall sufficient
Nov 2.2" 4.5" 0" ✅ Rainfall sufficient
Dec 4.6" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Tuscaloosa 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 ~1,640 GDD — county provides 4,756 GDD Excellent fit

Vinca (Annual) Planting Timeline — Kellerman, AL

Vinca (Annual) Planting Calendar

Activity When Date Range
Start Indoors January 11 Jan 11 – Jan 25
Transplant Outdoors March 8 Mar 8 – Mar 22
Bloom May 17 May 17 – Oct 18

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

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: too_acidic

🗺️ USDA Zone

Zone 8b

📆 Growing Season

232 days in Tuscaloosa County

Growing Tips for Vinca (Annual) in Kellerman

Direct sow Vinca (Annual) outdoors after March 22 in Tuscaloosa County when soil has warmed and frost danger has passed.

With Tuscaloosa 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 →

When should I plant Vinca (Annual) in Kellerman, AL?

In Kellerman, AL, plant Vinca (Annual) after the last frost (around March 22) and before the first frost (around November 9). Best results when soil holds above 50°F.

What growing zone is Kellerman, AL for Vinca (Annual)?

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

Can Vinca (Annual) grow in Kellerman's climate?

Yes — Vinca (Annual) grows well in Kellerman's temperate climate. Kellerman averages a 232-day frost-free season, with last frost around March 22 and first frost around November 9.

🌱

Your Tuscaloosa County Garden Planner — Free

A 22-page printable planner built for Tuscaloosa 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 Tuscaloosa County, AL. Local conditions may vary. Last updated: July 2026.