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

Coke County, Texas Zone 8a June

Your June gardening checklist

A quick June briefing for Coke County, Texas gardeners — what's urgent, what's next, and what can wait.

Avg. last frost March 24
Avg. first frost November 12
Soil temp (4") 73°F
Watering High
Pest pressure High
Daylight 14.1 hrs
  1. Begin indoor sowing: vinca (annual)

    You're about 21 weeks out from your last frost — the perfect window to get these germinating indoors.

  2. Basket week: vinca (annual)

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

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.

Coke County, Texas is in USDA Zone 8a. The average last spring frost is March 24 and the first fall frost is November 12, giving you a growing season of approximately 233 days.

At an elevation of 3,031 feet, Coke County receives approximately 52.1 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96°F, so Vinca (Annual) may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Vinca (Annual) will need more frequent watering and organic matter to retain nutrients. 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
Coke County, TX (Zone 8a) Long season
233 days
Last Spring Frost March 24
233 growing days
First Fall Frost November 12
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Coke County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.5-8.6

Drainage

Well Drained

Vinca (Annual) Planting Risk Windows

Early Start (70% safe) ✓ Fits season (29 days to spare)
Start indoors: Jan 5 Transplant: Mar 9 🌸 Bloom: May 18 – Oct 5
Recommended (50%) ✓ Fits season (30 days to spare)
Start indoors: Jan 13 Transplant: Mar 17 🌸 Bloom: May 26 – Oct 13
Safe Start (90%) ✓ Fits season (23 days to spare)
Start indoors: Feb 3 Transplant: Apr 7 🌸 Bloom: Jun 16 – 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 Coke County

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

Soil pH

Your soil pH (7.5–8.6) is more alkaline than Vinca (Annual) prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Coke County warms quickly in spring but drains fast. Vinca (Annual) will need more frequent watering and regular compost additions to retain nutrients.

Organic Matter

Organic matter is low (1.0%). Add 2-3 inches of compost before planting 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 233-day season

Sow every 8 weeks. Last sowing by Aug 14 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
Drought risk

Water stress score is 8/10 — 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 3.5" 0" ❄️ Dormant
Feb 3.4" 0" ❄️ Dormant
Mar 2.2" 3.2" 0" ✅ Rainfall sufficient
Apr 2.2" 1.7" 0.5" 💧 Light watering
May 2.2" 1.1" 1.1" 🚿 Regular watering
Jun 2.2" 1.9" 0.3" 💧 Light watering
Jul 2.2" 8.4" 0" ✅ Rainfall sufficient
Aug 2.2" 11.8" 0" ✅ Rainfall sufficient
Sep 2.2" 6.7" 0" ✅ Rainfall sufficient
Oct 2.2" 4.1" 0" ✅ Rainfall sufficient
Nov 2.2" 2.7" 0" ✅ Rainfall sufficient
Dec 3.6" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Coke 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 5,126 GDD Excellent fit

Vinca (Annual) Planting Timeline — Coke County, TX

Vinca (Annual) Planting Calendar

Activity When Date Range
Start Indoors January 13 Jan 13 – Jan 27
Transplant Outdoors March 17 Mar 17 – Mar 31
Bloom May 26 May 26 – Oct 13

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: too_alkaline

🗺️ USDA Zone

Zone 8a

📆 Growing Season

233 days in Coke County

Growing Tips for Vinca (Annual) in Coke County

Direct sow Vinca (Annual) outdoors after March 24 in Coke County when soil has warmed and frost danger has passed.

Sandy soil in Coke County dries quickly — mulch Vinca (Annual) with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 96°F in Coke 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 Coke County, TX?

Coke County is in Zone 8a with an average last frost of March 24. Plan your Vinca (Annual) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Coke County, TX?

Coke County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 24 and first fall frost is November 12.

🌱

Your Coke County Garden Planner — Free

A 22-page printable planner built for Coke 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 Coke 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.