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

Terrell County, Texas Zone 8b June

This month in Terrell County, Texas

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

Avg. last frost March 2
Avg. first frost November 27
Soil temp (4") 71°F
Watering High
Pest pressure High
Daylight 13.9 hrs
  1. Bring in the vinca (annual)

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

July prep starts now
  • 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.

Terrell County, Texas is in USDA Zone 8b. The average last spring frost is March 2 and the first fall frost is November 27, giving you a growing season of approximately 270 days.

At an elevation of 3,434 feet, Terrell County receives approximately 45.8 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.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant
Terrell County, TX (Zone 8b) Year-round
270 days
Last Spring Frost March 2
270 growing days
First Fall Frost November 27

Terrell County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.3-8.4

Drainage

Well Drained

Vinca (Annual) Planting Risk Windows

Early Start (70% safe) ✓ Fits season (66 days to spare)
Start indoors: Dec 11 Transplant: Feb 5 🌸 Bloom: Apr 16 – Sep 17
Recommended (50%) ✓ Fits season (60 days to spare)
Start indoors: Dec 22 Transplant: Feb 16 🌸 Bloom: Apr 27 – Sep 28
Safe Start (90%) ✓ Fits season (53 days to spare)
Start indoors: Jan 11 Transplant: Mar 8 🌸 Bloom: May 17 – Oct 18

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 Terrell County

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

Soil pH

Your soil pH (7.3–8.4) is more alkaline than Vinca (Annual) prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Terrell 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)

4
successive plantings in your 270-day season

Sow every 8 weeks. Last sowing by Aug 29 to harvest before frost.

Vinca (Annual) Water Budget

Plant needs
0.5″/week
Rainfall provides
0.7″/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 3" 0" ❄️ Dormant
Feb 2.4" 0" ❄️ Dormant
Mar 2.2" 2.8" 0" ✅ Rainfall sufficient
Apr 2.2" 1.7" 0.5" 💧 Light watering
May 2.2" 1.1" 1.1" 🚿 Regular watering
Jun 2.2" 1.7" 0.5" 💧 Light watering
Jul 2.2" 7.7" 0" ✅ Rainfall sufficient
Aug 2.2" 9" 0" ✅ Rainfall sufficient
Sep 2.2" 5.6" 0" ✅ Rainfall sufficient
Oct 2.2" 4.9" 0" ✅ Rainfall sufficient
Nov 2.2" 2.5" 0" ✅ Rainfall sufficient
Dec 3.4" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Terrell 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 5,940 GDD Excellent fit

Vinca (Annual) Planting Timeline — Terrell County, TX

Vinca (Annual) Planting Calendar

Activity When Date Range
Start Indoors December 22 Dec 22 – Jan 5
Transplant Outdoors February 16 Feb 16 – Mar 2
Bloom April 27 Apr 27 – Sep 28

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

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Transplant Outdoors
March Transplant Outdoors
April Bloom
May Bloom
June Bloom
July Bloom
August Bloom
September Bloom
October
November
December Start Indoors

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 8b

📆 Growing Season

270 days in Terrell County

Growing Tips for Vinca (Annual) in Terrell County

Direct sow Vinca (Annual) outdoors after March 02 in Terrell County when soil has warmed and frost danger has passed.

Sandy soil in Terrell 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 Terrell 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 Terrell County, TX?

Terrell County is in Zone 8b with an average last frost of March 2. Plan your Vinca (Annual) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Terrell County, TX?

Terrell County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 2 and first fall frost is November 27.

🌱

Your Terrell County Garden Planner — Free

A 22-page printable planner built for Terrell 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 Terrell 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.