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When to Plant Vinca (Annual) in Mason County, TX

Mason County, Texas Zone 8b June

June to-do list for Mason County, Texas

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

Avg. last frost March 25
Avg. first frost November 11
Soil temp (4") 71°F
Watering Low
Pest pressure High
Daylight 14 hrs
  1. Get vinca (annual) seeds going inside

    These need a head start before your last frost (March 25). Sow into cells now so you're ready to transplant in a few weeks.

  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.

July will be here before you know it — start on
  • 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.

Mason County, Texas is in USDA Zone 8b. The average last spring frost is March 25 and the first fall frost is November 11, giving you a growing season of approximately 231 days.

At an elevation of 4,557 feet, Mason County receives approximately 49.9 inches of rainfall annually with predominantly loam soil. Summer highs average 91°F, providing good warmth for Vinca (Annual) during the growing season.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant
Mason County, TX (Zone 8b) Long season
231 days
Last Spring Frost March 25
231 growing days
First Fall Frost November 11
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Mason County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.5

Drainage

Well Drained

Vinca (Annual) Planting Risk Windows

Early Start (70% safe) ✓ Fits season (21 days to spare)
Start indoors: Jan 2 Transplant: Feb 27 🌸 Bloom: May 8 – Oct 9
Recommended (50%) ✓ Fits season (21 days to spare)
Start indoors: Jan 14 Transplant: Mar 11 🌸 Bloom: May 20 – Oct 21
Safe Start (90%) ✓ Fits season (17 days to spare)
Start indoors: Feb 4 Transplant: Apr 1 🌸 Bloom: Jun 10 – Nov 11

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 Mason County

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

Soil pH

Your soil pH (6.5–7.5) overlaps with Vinca (Annual)'s range (6.0–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Vinca (Annual).

Organic Matter

Organic matter is moderate (2.2%). 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 231-day season

Sow every 8 weeks. Last sowing by Aug 13 to harvest before frost.

Vinca (Annual) Water Budget

Plant needs
0.5″/week
Rainfall provides
0.9″/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 1.3" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 2.2" 2.9" 0" ✅ Rainfall sufficient
Apr 2.2" 4.6" 0" ✅ Rainfall sufficient
May 2.2" 7.7" 0" ✅ Rainfall sufficient
Jun 2.2" 8.3" 0" ✅ Rainfall sufficient
Jul 2.2" 6" 0" ✅ Rainfall sufficient
Aug 2.2" 6.3" 0" ✅ Rainfall sufficient
Sep 2.2" 4.8" 0" ✅ Rainfall sufficient
Oct 2.2" 3.4" 0" ✅ Rainfall sufficient
Nov 2.2" 1.5" 0.7" 💧 Light watering
Dec 1.4" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Mason 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 4,215 GDD Excellent fit

Vinca (Annual) Planting Timeline — Mason County, TX

Vinca (Annual) Planting Calendar

Activity When Date Range
Start Indoors January 14 Jan 14 – Jan 28
Transplant Outdoors March 11 Mar 11 – Mar 25
Bloom May 20 May 20 – Oct 21

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 8b

📆 Growing Season

231 days in Mason County

Growing Tips for Vinca (Annual) in Mason County

Direct sow Vinca (Annual) outdoors after March 25 in Mason County when soil has warmed and frost danger has passed.

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 Mason County, TX?

Mason County is in Zone 8b with an average last frost of March 25. Plan your Vinca (Annual) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Mason County, TX?

Mason County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 25 and first fall frost is November 11.

🌱

Your Mason County Garden Planner — Free

A 22-page printable planner built for Mason 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 Mason County, TX. 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.