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When to plant Vinca (Annual) in Smith County, MS

Plant Vinca (Annual) in Smith County during the brief February 27–March 13 window. With 245 frost-free days, fall plantings can't mature before November 13.

When to Plant Vinca (Annual) in Smith County, MS

Smith County, Mississippi Zone 8b June

Smith County, Mississippi gardeners: here's your June plan

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

Avg. last frost March 13
Avg. first frost November 13
Soil temp (4") 83°F
Watering Low
Pest pressure High
Daylight 14.1 hrs
  1. Collect vinca (annual) at their peak

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

Looking ahead to 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.

Smith County, Mississippi is in USDA Zone 8b. The average last spring frost is March 13 and the first fall frost is November 13, giving you a growing season of approximately 245 days.

At an elevation of 492 feet, Smith County receives approximately 58.4 inches of rainfall annually with predominantly clay loam soil. Summer highs average 96°F, so Vinca (Annual) may need afternoon shade and extra watering during peak heat. 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
Smith County, MS (Zone 8b) Long season
245 days
Last Spring Frost March 13
245 growing days
First Fall Frost November 13

Smith County Soil Profile

Soil Type

Clay Loam

Soil pH

5.7-6.5

Drainage

Well Drained

Vinca (Annual) Planting Risk Windows

Early Start (70% safe) ✓ Fits season (34 days to spare)
Start indoors: Dec 26 Transplant: Feb 20 🌸 Bloom: May 1 – Oct 2
Recommended (50%) ✓ Fits season (35 days to spare)
Start indoors: Jan 2 Transplant: Feb 27 🌸 Bloom: May 8 – Oct 9
Safe Start (90%) ✓ Fits season (26 days to spare)
Start indoors: Jan 27 Transplant: Mar 24 🌸 Bloom: Jun 2 – Nov 3

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 Smith County

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

Soil pH

Your soil pH (5.7–6.5) overlaps with Vinca (Annual)'s range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.5%). 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)

4
successive plantings in your 245-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
1.0″/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 5.2" 0" ❄️ Dormant
Feb 5.1" 0" ❄️ Dormant
Mar 2.2" 5.6" 0" ✅ Rainfall sufficient
Apr 2.2" 3.8" 0" ✅ Rainfall sufficient
May 2.2" 4.6" 0" ✅ Rainfall sufficient
Jun 2.2" 5.2" 0" ✅ Rainfall sufficient
Jul 2.2" 6" 0" ✅ Rainfall sufficient
Aug 2.2" 5.1" 0" ✅ Rainfall sufficient
Sep 2.2" 4.8" 0" ✅ Rainfall sufficient
Oct 2.2" 4.1" 0" ✅ Rainfall sufficient
Nov 2.2" 4.2" 0" ✅ Rainfall sufficient
Dec 4.7" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Smith 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 ~1,760 GDD — county provides 5,390 GDD Excellent fit

Vinca (Annual) Planting Timeline — Smith County, MS

Vinca (Annual) Planting Calendar

Activity When Date Range
Start Indoors January 2 Jan 2 – Jan 16
Transplant Outdoors February 27 Feb 27 – Mar 13
Bloom May 8 May 8 – Oct 9

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

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Transplant Outdoors
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: acceptable

🗺️ USDA Zone

Zone 8b

📆 Growing Season

245 days in Smith County

Growing Tips for Vinca (Annual) in Smith County

Direct sow Vinca (Annual) outdoors after March 13 in Smith County when soil has warmed and frost danger has passed.

With Smith 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.

With summer highs reaching 96°F in Smith County, provide afternoon shade for Vinca (Annual) and water deeply in the morning.

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 Smith County, MS?

Smith County is in Zone 8b with an average last frost of March 13. Plan your Vinca (Annual) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Smith County, MS?

Smith County, Mississippi is in USDA Hardiness Zone 8b. The average last spring frost is March 13 and first fall frost is November 13.

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

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

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

Smith County 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 Smith County's climate?

Yes — Vinca (Annual) grows well in Smith County's temperate climate. Smith County averages a 245-day frost-free season, with last frost around March 13 and first frost around November 13.

🌱

Your Smith County Garden Planner — Free

A 22-page printable planner built for Smith 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 Smith County, MS. 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.